How to optimise the Facebook Ad Algorithm

April 16, 2019

Facebook’s advertising algorithm is a mystical creature that we all know can seem whimsical at times. If you give it what it needs, however, it can be your most powerful helper. In this blog, we cover top tips on how to help the Facebook advertising algorithm do its magic and get consistently great results.

How does the Facebook advertising algorithm work?

The truth is that Facebook’s advertising algorithm is understood by very few. That being said, having an understanding of the main forces behind it is important if you are to create successful Facebook advertising campaigns. Here we will try to demystify the Facebook ad algorithm and give you a simple framework for understanding how it works.

The order in which your ad appears in relevance to other ads is determined by an auction. Facebook’s main focus is creating a great user experience which is why its advertising algorithm doesn’t give the highest priority to the highest bidder in the auction and takes into account user experience factors. The main factors Facebook looks at when deciding what ad should get the highest priority are bidding, estimated action rate and user value.

Facebook’s estimated action rate is a prediction on how likely the ad is to generate engagement (likes, shares, video views, website clicks). The user value component looks at the experience a user has after they click an ad. If users are back-clicking from your ad, for example, because the landing page they were taken to wasn’t relevant or mobile friendly this will negatively affect your ad’s performance. All those factors together determine what priority your ads will be given in the auction.

How to optimise the Facebook Ad Algorithm

The best thing you can do for your Facebook ad campaigns is to let the algorithm do its thing. Here we outline what the Facebook ad algorithm needs from you to be able to work its magic and deliver you great results.

Be careful what you wish for

The first thing the Facebook algorithm needs is to be told what to do. You do that by setting your campaign’s objective. The objective tells the algorithm what conversion event it should optimise for. Facebook’s algorithm is really good at getting you exactly what you ask for so you need to carefully plan and set your campaign objective.

If you tell Facebook that you are after purchases, for example, it will do its best to give you just that. Similarly, if you set your objective to Clicks you will most definitely get clicks but those clicks might not necessarily land you sales. Work out what is the most important conversion event for your campaign and make sure Facebook knows that.

Also, make sure that you have chosen the correct window of data to optimise to. Facebook looks at conversions made over a rolling timeframe to learn from. Depending on the amount of data you are collecting, you can set that to a specific timeframe. A  standard recommendation is using a 7-day window but if you are working with lots of data you might want to set that window to 24 hours for accelerated learning.

Target a large audience

Gone are the days of creating hundreds of small audiences. The more data the algorithm has to play with the better it is at predicting how well it will perform. Give the Facebook algorithm enough data to work with and you will have a campaign that performs well for a longer period of time before it decays.

Get 10+ actions a day

Facebook’s algorithm needs enough data to do its job. The algorithm needs to get at least 10 actions a day to learn from and optimise your campaign properly. If you are getting less than those 10 actions, the algorithm will kill the delivery of the ad as it struggles to optimise for your objective and you will start to see a decline in performance.

For example, it is a great idea to optimise for purchases, however, if you are not getting 10 purchases a day from your campaign its delivery will probably go down. In that case, you might want to try optimising for a conversion which is likely to generate enough actions such as added to cart so that you allow the algorithm to work harder.

Set a high enough bid price

The higher the bid price the more auctions you can compete in. Paying a higher CPM to reach people more likely to buy pays off as it lowers your CPA which is the metric you really need to care about. Don’t try to save money by bidding lower as this won’t drive return on investment.

Don’t stop start the campaigns

When you stop and restart your campaign Facebook will lose all the historical data that the algorithm needs to perform well. This will practically reset your campaign back to square one as Facebook will take a few days to relearn everything.

Don’t break the 20% text rule

The 20% text rule refers to the amount of text that can appear on an ad image. Facebook will penalise you in the auction if more than 20% of your image is taken up by text. Use text sparingly in your ad images for better performance.

All ads decay

All good things must come to an end and that includes even the best of your Facebook campaigns. It is important to know how to spot if your ad is decaying and when to take action. The lifespan of your campaign depends on the engagement it generates, the audience size, the number of conversions and whether you are within your target CPA.

You will know that your ad is decaying when you see your CPR increasing and your CTR dropping. The best solution to this is to always have 3 ads in an ad set. Review performance regularly and once a week pause the worst performing ad and replace it with a new one.

The sale campaign effect

Let’s say that you have decided to run a sale and want to promote that with some Facebook ads. If you have set your campaign objective as Website conversions the Facebook algorithm will be working hard on getting you the best CPA (cost-per-action) with the highest volumes for the goals you set. If the algorithm thinks it’s failing i.e the CPA is higher than your bid price it will restrict delivery and the campaign will die.

In this case, your campaign might see a great spike in performance while the sale is running as your conversion rate from impression to sale goes through the roof with the offer and you start hitting your bidding goals. When this happens the algorithm increases delivery and finds loads of willing buyers.

If you decide to keep the same campaign running with the same daily budget after your sale period ends, however, your CPA will go up, the algorithm will have less data to work with and you will likely go over your target CPA so the algorithm will cap delivery. To fix this, you either need a non-sale creative that performs on par, or you need to be prepared for a perpetual sale cycle!

To learn more, check out The ultimate Facebook Lead Ads guide.

Get Started Free with Driftrock!