I've personally had very little success (I'm a tad bitter at the moment, as a girl I was seeing who I met online just posted that she's in a relationship with someone else.) To actually answer your question, I have some friends who have had quite a bit of success online. I know a couple who met on OkCupid and have been happily married for (I think) 3 years. Another couple met on Tinder and have been living together for almost 2 years.
To speak from personal experience, while I haven't had success, most people who come up on OkCupid in the high-percentage compatibility work in or enjoy seeing theatre. I like OkCupid because of the compatibility percentage.