A lot of punters seek Milfs out for a couple of reasons...they're older guys who are more comfortable with someone closer to their age group (myself personally, I would feel stupid for banging an 18yo), or for the "special services" many invariably offer to maintain competitiveness with other, younger ladies (bareback, anal, hard fetishes).
The other thing...those pics are really heavily shopped...so you're more or less reduced for going for the service levels, unless you have an old lady fetish. Anna and Cici are obviously hiding a gut, and Perrier likely has some serious stretch marks, judging from the p-shopping. In other words...
caveat emptor!