Interest groups & lookalikes, and retargeting audiences will always be smaller than just focusing on age, gender, and location. Not only are these audiences much smaller, but the information used by Facebook to figure out who is in the audience is very inaccurate. Repeated studies have shown that at least 30% of any interest group is there by mistake and that sometimes more than half of the users in an interest group are there not because they have the intent to buy something but because they actually dislike the thing that they talk about often, which is how they were in the interest group, to begin with.
Another downside of interest groups and look-alike audiences is that they will always fatigue. You will eventually have to turn them off because the performance got so bad. However, broad or open targeting will continue to improve over time because Facebook is a machine-learning algorithm, and you are letting it learn who you want to spend money on.
You can try to find audiences that behave well for your business and chase that performance with more &more creative testing. Ultimately these ad sets will only get worse, and you’ll have to start over, and Facebook will be a little more expensive when you do.
Or you can make ads that are designed to appeal to specific people throughout your marketing funnel and let Facebook find the right ones to show ads to every single day in a way that will let Facebook get better and better at that decision making which means your performance will continue to improve over time.
Broad is stable, projectable, and cheap. This means we can have the highest confidence in future outcomes, and you’ll never need to use anything else.
Broad also never fatigues because it is quite literally everyone!
Broad also provides no restriction to the users that your ads are most appealing to. This means your ads will always be shown to the best people!
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