Late to the party on this thread, but yes online dating gets more difficult by the day.
Five years ago on POF alone I was guaranteed to mess around with several new girls a month, getting laid and one night stands were pretty frequent. Tons of ongoing flings. Text book plate spinning basically. Reflecting back on 2015 that number dwindled drastically, only slept with one girl from tinder that I had a 3 months fling with (granted I did turn down sex from a few girls). Overall much harder to get dates, even harder to get a second date. I realize I'm five years older now, but physically I'm the same physique and people always tell me I still look mid-late 20's.
I think more guys with game and looks started flooding the dating sites. Crap like Instagram, Snap Chat, Tinder have all come to fruition which has doubled or tripled women's options even further. I don't know, but I do know that lots of guys are having the same frustrations. 80/20 theory more apparent than ever.