Girls on POF are overwhelmed with come-ons from pervs, no matter how conservative their photo and profile are. If you message them your odds are crap. Why would they pick you over the other 120 guys who messaged them that week? If they message you there's a chance. If you're not great looking, then you're not going to win over the other guys, and if you are, then in their minds your pic is likely fake, so they won't bother.
AFF is total garbage. Sausagefest. It has a worse M to F ratio than POF, which they hide with tons of fake profiles. There are some escorts on there, which I imagine are the only ones you have a chance of ever meeting, and the price is likely the same. Flirts and emails from fake members are the norm. Real girls will ignore you unless they are brand new.
The underlying problem I believe is the ratio. I've been turned down by girls on these sites, that would approach me offline. In fact, I met a girl out in the real world, who ignored me on pof, and she was thrilled to go for a date when I asked her in person (not mentioning that I had messaged her on pof). I suppose if we had a few girls each day messaging us for sex, it would be easy to miss out on the gems who were serious and worthwhile.
The only way I've had any success with either site (and it wasn't worth it) was to let them message me, send a few pics of myself so they know I didn't just a fake one I found online, and get slightly pushy. (Ie "so where are we going to meet for dinner?" rather than "do you think we can meet for dinner.") Also, however nice your compliment about her appearance might be, leave it out of your first few messages because it's gonna come off as desperate annoying BS rather than flattering. Be honest about yourself, if you're married then say it, if you're fat then say it, and point out if you don't smoke, drink, point out if you have a nice place to host and a vehicle, point out that you shower and brush your teeth before going out, point out that you have a good job and you're not a criminal or dropout. That stuff counts a lot more than a pic of your dick. You're just one ad in a catalog to them so make it count.
I had success once with a well-written craiglists ad and a good torso pic. I had to deal with replies from fake girls, and gay dudes, though. I think 12 worthless replies for one good one, and I think that one good one was a fluke.