Do people in your target audience suffer from ad fatigue?
As much as some people say the average frequency to get a conversion have increased from 7 to 12 nowadays, there is also an inverse correlation with frequency and conversion rate beyond a certain point.
Also, are the ads themselves different? This can potentially work if the ad copy and format are different across the different campaign and you treat everyone coming in from the different campaigns differently.
For example,
B2B lookalike campaign: the people get ad variation A and a landing page that addresses a particular need/problem
CTA can be download a white paper
Retargeting campaign: people get an offer and/or book a demo to lock in a discount
Purchased list campaign: join a webinar
I’m also 90% sure that even within these different audiences, people may be in different parts of their purchase decision journey so even if you just hone in on one of these audiences, you may still be able to make a lot of optimizations within the campaign
You may also want to create audiences for everyone who’s clicked through from each of these campaigns and potentially exclude these audiences from the other campaigns you’re able to fence people into one funnel/experience