I could be wrong, but I think it only counts the first one (for the over all wifi rating displayed at the bottom under your profile stats when you post), and all the others appear on the logs on your profile, but don't contribute to your overall wifi rating percentage
eg; if you have 2 wifi ratings, one negative, and one positive - then you're rating will be 50%, but if the person who gave you a positive gives you another rating, instead of it moving up to... 66%?? (idk how to math sorry), it will stay at 50%, because it only counts unique ratings, so someone else will need to give you a rating to change it.
I also think there's a cool down time between ratings?
So I don't think there's really a way to abuse it, since pretty sure it only counts the first rating you receive from a person, but for me personally, if I were to trade with someone, and saw they had like 523329 ratings from the same person, i might be hesitant to trade with them coz it looks suspicious (but i dont think people actually scroll through the logs anyway, main thing is they look for a good rating, and if they have a bad rating, then they'll see what it was for and make a decision from there)
idk i havent used the rating system for a long time, but back when I did this is what I seemed to remember - could be totally wrong.
