Hi,
every search term will likely have different conversion rates so I imagine that’s a tough question to answer past their site’s general average which won’t really tell you a whole lot because you’d not really know whether the site was successful based on its selling ability or the terms it targets for traffic?
and I doubt many will be eager to offer optimistic numbers for keywords because that would be like saying “hey i do good with this keyword so why don’t I try to increase my competition for ranking for it?”
I will say one time i converted 1 in 25 for a freebie offer but it never amounted to anything because the casino offering it turned out to be one you’d probably not care to have listed. Took me about 3 months to figure out they were never going to make me money and it didn’t matter if I was going to convert at 100%.