I've gotten ads for that thing too. I think it's because Google ads really only knows that you're on social media and little more so it just shoves ads for "social media" at you and then this happens. I think, at least kinda, that it's reassuring seeing ads so disconnected from my usage of the app since it implies little information is being sent to third party advertisers.

Next time I get paid I'll just pay the dev though tbh