First of all, Moaform has no limit on the number of responses that can be collected regardless of whether you use BASIC, PLUS, or PRO.
In the case of BASIC and PLUS plan, after respondents submit their responses, they will be directed to the Thank you page, and the ad banner is always displayed on it.
In the case of PRO plan, respondents will not be exposed to ad banner until the number of responses reaches 5,000 for a month if you purchased monthly PRO plan, and the ad banner will be exposed from the 5,001th case. For annual plan users, respondents are not exposed to up to 75,000 within the service usage period. Even if it exceeds 5,000 per month or 75,000 per year, you can still collect an unlimited number of responses. It only affects to whether ad banners are exposed or not.
For reference, since the ad banner is only exposed after the response is submitted and saved, it does not affect the response completion rate at all.
Moaform uses the Google AdSense ad platform.