Website Custom Audience is a great tool for advertisers on Facebook as it offers the chance to advertise directly to anyone who has already visited your website. The benefits of being able to target specifically in this way are multi-fold:
Targeting an audience who have already shown an interest in your product or service
Re-targeting previous customers
Capturing the attention of lost customers who did not complete a transaction
In order to allow Facebook access to your website visitors they create and send you a unique pixel, a snippet of code you need to copy and paste in between the HEAD tag of each page on your site. You are then able to create lists from this tracking device, including from specific pages and also timespan. So for instance you could provide Facebook with a list of people who had visited your shopping basket page over the last three months but who had not visited the completed page.
Facebook use these lists to send your targeted adverts to on their own site.
As effective as this Facebook advertising product is, where it fails is with its lack of ability to cater to multi-site owners or third-party advertisers who look after multiple clients. With each advertising account you are given one pixel to add to a website – although it is technically possible to add this to a number of websites, logistically speaking this is not practical nor advisable.
The best solution really would be for Facebook to offer a solution which better caters for multiple sites however in the meantime there are a couple of ways around this problem:
Get added to your clients Facebook advertising account
If you are a third party advertiser advertising on behalf of a number of clients the simplest way around this issue is to add yourself to their account so you can operate independently between different clients.
Your client will have to go to:
Ad account roles
At this stage they will need to add your name from your Facebook profile or your email address to link you to their account. They will need to select your relationship with this account which will be ‘Ad Account Advertiser’.
With URL rules
The above solution works well for clients who own one site or for advertisers with only one site. Where it doesn’t is when a client has multiple sites or when a direct advertiser own more than one. If this is the case you will need to add the single pixel to all of your sites (or all of your client’s sites on their account that you need to be added to) but create distinct lists via URL rules.
In the same way you create lists with page and date parameters you can differentiate the target list for Facebook through URLs. You need to change the list criteria to include specific pages and then add the rule to only include parts of a specified URL. Add the name of the website here in order for the list to retrieve pages from that site only.
This way the list will only ever contain users who have visited that specified website.
Although these methods incur a bit of extra time and trouble they do still result in accurate tracking and targeted adverts accordingly. Until Facebook come up with a better solution to suit advertising accounts with multiple sites attached these look the best way of getting around that.