Don't have a use for dating websites, but I see them all kinda the same, just like social media. It's basically a calling card, a way to say "this is me, this is who I am, feel free to get in touch." Like, you meet someone cool of the super-rare "random stranger" variety and you don't have a lot of time, you ask if she's on any dating sites and exchange info and hook up from there.
All you do with that is hedge your bets and keep your options open to the online community. That's all. Unless you're open to a fantasy exclusively online gf that likely isn't devoted to you in meatspace, something absolutely MUST happen IRL. Anything apart from that is pointless.
Plus, from what I've seen people post here about Tinder and PoF, they seem like perfectly useless sites.
Back in "the day," I was an IRC addict and relentlessly flirted with girls in ways I'd never dream of offline. I only met up with three of those, and none of them progressed beyond a first date (actually, I only got one "real date" out of that). It doesn't look like much has changed.