I had a couple cases of brushing lips, then had my first full kissing session a couple months ago. I thought it was great at first, but the next week she barely remembered me, and the week after that she remembered my face but not name or what we talked about. Based on that, it was pretty clear that I wasn't the only one getting this type of treatment. I really didn't care about the other guys, but got a little freaked out last week when I came down with a nasty kanker sore. It cleared up fortunately, but got me thinking of the oral herpes risk and how it might not be worth it (then again you can get that from kissing your grandma or borrowing someone else's chapstick).
I don't think she kisses every guy she dances with, but know I'm not the only one getting extras for "free". As you might expect, she's the type that is selective in who she approaches and hits you with the extras without asking. Needless to say, both myself and every other guy I've seen her with goes at least 3 dances. So, I consider the kissing part of her sales strategy. If you like it and she's doing it, more power to you. I'm sure lots of guys would kill for a good kiss from their favorite. But, remember you're paying money for her time and are probably not the only one getting similar treatment.