The Practical Retargeting Guide

retargettingThis retargeting guide has been provide by guest contributor Daryl Mander.

What Is Retargeting?

Retargeting is the practice of showing your ads to users who have previously been to your website. You’ve probably noticed retargeted ads on the web before, you might have been to an ecommerce site recently only to be shown banner ads the next day showing the exact site you went to and in some cases even the exact products you were looking at.

It’s a powerful form of online display advertising, because you are targeting people who have already shown an express interest (by visiting your site) in your product or service.

How Does It Work

The way retargeting works is users who visit your site are tracked with cookies using code given to you by your retargeting supplier. When they visit other sites on the web, you are then able to serve them the retargeted ad (see image below).


Image courtesy of (click for a larger image)


Is It Right For Me?

Whereas traditional display advertising is used mostly as an awareness and brand-building tool, retargeted display ads are great for driving conversions on your site, be they sales, sign ups, leads, subscribers etc.

If the goal of your advertising campaign is direct sales or signups and you have a decent amount of traffic then retargeting is ‘right’ for you (more on traffic below).

What Results Should I Expect?

Compared to standard display advertising, you should expect vastly improved click through rates (CTR’s) and conversion rates from retargeted advertising. To illustrate with an example, let’s look at standard display advertising’s CRT’s versus CTR’s of retargeting.

  • An ‘average’ display ad campaign will generally get a CTR of .05%-0.1%.
  • Retargeting, on the other hand, will often average out at around .2% (at least double).

Looking at conversion rates, I’ve worked with clients where their typical site conversion rate came in at 2%, but retargeted traffic converted at 20%. This type of result is by no means uncommon; it is the rule rather than the exception. Especially when you throw dynamic creative (more on this later) into the mix, you’ll be looking at monstrously high conversion rates compared to your site average.

Getting Started – Thresholds

There is a minimum threshold audience size that you should have before starting a retargeting campaign. Retargeting, by definition, only targets your current site audience. If your site only has a small amount of visitors per month, you will only have a small pool of users to target, and thus sales volumes will be very low.

My recommendation is to start at 5,000 unique visitors per month. If you currently have less than 5,000 uniques, add a retargeting tracking pixel to your site now but don’t start retargeting yet. This will start building your pool of retargetable users.

Leave the tracking pixel there for a few months while you work to scale your traffic levels. Then, when you do start your retargeting campaign, you’ll have a more significant pool to target. Further on in this guide we’ll discuss some options for providers.

Getting Started – Step By Step

The exact process for getting your retargeting campaign can vary but what I’ve got here for you is the overview of the process.

Identify your target CPA

It’s important to know what your target CPA (cost per acquisition or cost to acquire a customer) is before starting out your campaign. Having a very clear idea of your target CPA will help with measurement of the campaign and with optimization later down the line.

The higher your CPA, the more ad inventory you can afford, and thus the quicker you can scale the campaign. Consider the life-time-value of your customer by factoring in average repeat purchases to find your absolute maximum CPA tolerance.

Select your retargeting supplier

We will go into more detail on providers further on in this guide but in this example we have chosen AdRoll.

Set up a campaign

The procedure for this will be different given the provider but here are the steps for AdRoll.

Step 1 – Visit AdRoll and sign up for a free trial


Step 1 – Enter your campaign name once you are in the system

Give your campaign a name that makes sense then click ‘Create’. Note in the screenshots below you can click the image to show a larger version.


Step 2 – Upload your ads

Click ‘Create a New Ad’ and enter the details then upload your creative.



Step 3 – Enter payment details

Enter your payment details which are used to identify you. You won’t be charged until you set a budget on a campaign. You are even given $60 worth of ads for free to get you started (or at least I was – maybe I’m special?).

Step 4 – Add the tracking pixel

The tracking pixel code needs to be added to your website for the retargeting to work. I’m using WordPress so I went into Appearance / Editor and added the code into the header.php file. If this sounds scary then get your web developer to do it.


You will also have the opportunity to set a conversion pixel. This will differ for every person depending on your type of business. For example if you were running a recurring software business you would place it on your payment page to ensure that AdRoll can report on the successful conversion and also make sure the user isn’t shown the ads again.

Step 4 – Launch

Once your tracking pixels are in the page you’ll need to wait for the pixel to have dropped enough cookies on enough users for you for much to happen. If your site is small, this could take a while but eventually decent numbers of people who have been to your site will start seeing the ads.

Step 5 – Measure & refine 

Don’t think of your retargeting campaign as a ‘set and forget’ strategy. Measure its effectiveness versus your cost-per-acquisition targets as soon as you have conversions data. Refresh your creative at least once every 4 weeks to prevent viewers suffering from ‘banner blindness’. Have multiple creatives running at the same time and optimise towards top performing creative sets.

How Much Does It Cost?

Depending on which supplier you use and your media budget, the cost of the campaign will vary. You will usually pay for your media on a cost-per-click (CPC) or a cost-per-thousand-views (CPM) basis. For most self-serve platforms, including AdRoll there are no minimum spends and you can get started for as little or as much as you like.

Creative That Converts

First off I highly recommend that you have banner ad creative made in the following 5 top sizes:

  • 160×600
  • 120×600
  • 300×250
  • 468×60
  • 728×90

Here you can see them all displayed visually (click on the image for full size).


Image courtesy of (click for a larger image)

Yes, some sizes perform consistently better than others (here’s looking at you, 300×250) but when you are spreading your ads across a huge network of sites, you want as many opportunities to appear in front of your user as possible. The 180×150 recommended by the IAB is less commonly used, think of it as a ‘nice to have’ but not 100% necessary.

Dynamic Creative

zappos_retarget_cartabandonDynamic Creative means that the ad gets displayed to the visitor is tailored ‘dynamically’ to each user.

For example if I visited Zappos and looked at some women’s shoes (I didn’t really….I promise) then I might see an ad like the one on the right (i.e. the exact shoes I looked at).

This is generally suitable for sites with lots of products like ecommerce, travel, job sites etc and generally only available when you are running a large managed implementation (i.e. $5k per month minimum).

I’ll assume that most of Informly’s readers will be running the standard static ads.

Static Creative

If you are having static banner creative made, there are some points specific to retargeting banner creative you should take note of:

  • Differentiate: Make sure it is not just the same creative you use for your standard banner ads campaign. Differentiate it with specific messaging aimed at retargeted customers. Remember these customers know who you are already so you should be giving them a reason to click not a message informing them of what you offer.
  • Call To Action: Ensure your ad has a strong call-to-action, direct the user to actually click through by including a button with “Buy Now” or “Sign Up” etc.
  • Make An Offer: Banners with an offer or promotion get much higher click and conversion rates. A promo code for free postage or 10% off the product price might be all that’s needed to push that user over the edge and convert on your site.
  • Avoid Clutter: Pick one image, one message, and roll with it. Keep your design simple, uncluttered and focused. Users will easily tune out cluttered banner designs.

What Suppliers To Use


adroll_logoAdRoll’s known for having great customer service, an extremely high reach network, and no minimum spend. Their interface is detailed with tons of stats and reporting options. Their default pricing structure is based on CPM, however you can also set up on a CPC or CPA (cost per acquisition – for managed users see more below) as well, which lowers the risk considerably. AdRoll is the provider we’ve chosen to use in this example and is the provider Dan will be using for Informly.

Site Scout

sitescoutSite Scout are focused on catering to small business clients, entrepreneurs and digital agencies. The UI is easy to navigate and friendly and once again there are no minimum spends. They also offer a whole host of targeting solutions beyond standard retargeting, such as contextual, device, and geographical targeting.


bizoBizo differentiates themselves by specifically targeting B2B clients. They have large pools of targetable users who have demonstrated an interest in B2B ads in numerous categories through their browsing data. They also have a self serve, no minimum ad platform where you can set up a retargeting campaign. If you’re a B2B advertiser and want to branch out beyond just retargeting, Bizo’s the self serve platform for you.

Fully Managed Service

In addition to the self service platforms above there are also options for fully managed services. If your site is getting in excess of 50K unique users per month and you are looking to spend at least $5K per month on advertising, then this is the way to go.

AdRoll also offer a very comprehensive fully managed service including dynamic creative production. The rates are reasonable and the reach of their network is sufficient that you’ll be sure to reach the majority of your retargeted users next time they surf the web.

One of the global leaders in retargeting technology, Criteo specializes in cost-per-click based, performance-led display retargeting. They have no self-serve platform, they don’t cater for small advertisers, and their minimum spends are $5K. However, their CPCs are very competitive and they can reach 90% of users within 24 hours of visiting your site.

I hesitate to mention Criteo here because from an agency’s point of view, their customer service is poor, lacks any human edge, and they engage in highly uncompetitive practices. But, as a direct client who wants a CPC-focused full service retargeting solution, they are a good option to consider.

A UK based company, Merchenta offers global ad inventory. Being a bit smaller than Criteo and AdRoll, the service is more personal and highly recommended. Best aspect of Merchenta? They offer retargeting on a CPA basis – meaning you only pay when a sale is achieved.

It’s a compelling, low-risk offer. It’s normally priced on a %age of sale basis and depending on your volumes you’ll probably be looking at anywhere between 10-20% commission.

Measuring Effectiveness

When measuring the effectiveness of your retargeting campaign, look at the delivered cost per conversion versus the initial target you set out. One big thing to factor in to your measurement is that you must hold your retargeting campaign to a much stricter target than other channels. This is because there is likely to be a certain amount of sales cannibalization and duplication within the results:

  • Cannibalization: some of the users who you retargeted, who clicked a banner and came back to your site, would have converted anyway. Depending on the type of product you sell, users may be likely to convert only on the second, third or fourth visit to your site. For some users, they were in the sales funnel, about to convert anyway, and your retargeted display banner managed to jump into the funnel and ‘claim’ a sale that was going to happen regardless.
  • Duplication: If you are using a bunch of different packages to analyze your marketing then you might have some duplication. For example your PPC ads might show that they sent the buyer, your retargeting provider may say that they sent the buyer etc. If you are using the one central analytics package then you shouldn’t get this duplication.

Also the analytics service you use may behave differently for example if you are using Google Analytics, it will attribute the sale to the retargeting ad (most recent). If you are using Kiss Metrics you can set up reports for the first ever referrer / last ever etc.

It’s worth being aware of these things but in general unless you have a very sophisticated analytics package (DC Storm for example) that can analyze the whole process for you then you have to accept a little bit of imperfection.

A few ways you can manage the imperfection are:

  • You can measure the uplift in conversion rate driven by your retargeting campaign. For example you can look at a group of users who signed up while retargeting ads weren’t running and then look at a group that signed up while they were running (Kiss Metrics users can use Cohort Analytis for this). If retargeting is truly effective, you should expect it to increase the conversion rate of the group who were presented with the retargeting ads
  • You could use a rule of thumb and reduce your cost per acquisition target by 30% to be on the safe side.

This is a very rough rule of thumb based on my experience working with large advertisers who could afford to buy de-duplication software and afford to set up conversion rate uplift tests.

If you can afford neither, or simply don’t have the time to spare, work with the 30% rule for now until your traffic gets to a point where further analysis will provide a good ROI.

I’d love to know what you think!

I hope this guide was useful, if you have any feedback on the guide please feel free to ask questions below.

About The Author

darylDaryl Mander is a freelance digital marketer who specializes in performance display advertising and retargeting.

For a free consultation on your display or retargeting campaign, contact him via email.

Dan’s comment: I was totally blown away by the quality of this post. From now on every time someone asks be about guest posting I’m going to refer them to this. Daryl obviously knows his stuff so if you need help with retargeting make sure you get in touch with him. 


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Dan Norris is a co-founder at WP Curve and a passionate entrepreneur with an obsession for content marketing.

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