When IAC acquired OkCupid in 2011 for $50MM, OkCupid had almost as many users as Tinder does now, but Tinder's valuation (according to IAC) is literally 100x more.
I'm not sure OkCupid and Tinder should even be compared (despite OkCupid containing a clone of the Tinder app). This is purely from experience, but most people on Tinder use it solely as an ego prop - finding a date isn't the focus so much as the validation that comes with a match. You can even do some shoddy A/B testing with Tinder (if I lead with photo x, do I get a higher match rate than with photo y?), and I do think more advanced image testing/refinement tools could and should be a large part of their feature set going forward. OkCupid has something similar with the My Best Face feature, but they don't seem to have expanded further on that idea.
You could say that, feature-wise, Instagram was literally a subset of Foursquare, or Twitter was literally a subset of Tumblr (blogging) or Facebook (status updates). But how people actually interact with and use those platforms (and the value derived from those interactions) are very different.
That's true. Other thoughts: Tinder has flipped the traditional dating website model on its head. On OkCupid and others, people filter by black-box quantified "compatibility" first and then attractiveness. Tinder just puts attractiveness first and leaves compatibility scoring to the people themselves.
OkCupid recently introduced a feature where you can pay a small fee (about $1) to temporarily boost your personal search ranking. This is clever, and also fits very well in Tinder's matching model. Adding features like that or the ability to pay for additional profiles for A/B testing would put Tinder in the black pretty quickly, I think.
edit: I should throw in some negatives. There are quite a few duplicate/spam profiles on Tinder created by escort agencies. Finding a way to seamlessly detect & block these will be important to avoid a reputation of seediness. It's already on the line due to the common practice of mentioning Tinder alongside location-based hookup apps.
When IAC acquired OkCupid in 2011 for $50MM, OkCupid had almost as many users as Tinder does now, but Tinder's valuation (according to IAC) is literally 100x more.