That's BS and you know it. If that were the case, OP's startup should've bought ads on OKC and OKC would be glad to sell ad space. I really doubt that OKC or its parent company will sell ads to a competitor dating site.
1. OKC is a listing of profiles where the lister is expected to manage the transaction 2. The management of the transaction is a huge friction and pain point for a significant number of people (as is writing a profile, taking pics, etc...for which there are also people that help). 3. this service reduces/removes that friction/pain point for okc. 4. this service is NOT a listing of profiles (as far as I can tell) 5. this service does NOT discourage people from signing up for OKC, Match, POF, etc...in my view it encourages participation in those services (whether implicitly or explicitly).
If I'm missing the mark on any of the above, feel free to correct me.
As far as I understand it from the copy on Dating Ring's web page, their service is meant to replace all those dating sites. It's a fire-and-forget product that frees you from the need of maintaining an on-line profile and visiting a dating site - discouraging people from singing up for OKC is exactly what it is meant to do.
The thing is, marketing is mostly zero-sum game; people are stuck in a negative feedback loop of throwing more and more money to one-up their competitors at attracting customers from the same limited pool. It's an unlimited resource sink, but it's a) what you have to do lest you get outcompeted by others, and b) profitable for those who facilitate advertising.
Weixiyen is also right that this "growth hack" is effective, but remember that "growth hacking" is mostly a fancy term for spamming / abusing trust. Every new way to trick people into buying something will work for a while, until everyone else starts doing the same and the ROI drops to zero.
Once upon a time, a pop-up banner was the clever growth hacking trick. As HN's idlewords tells the story,
"One of the first banner ads had a click-through rate of 78%. That's mind-boggling. Do you know what two words were on that banner ad?
"Shop Naked!" CLICK!
But banner ads turned out to be like poison ivy. People clicked them once, and learned never to touch them again. The industry collapsed in a flurry of pop-overs, pop-unders, and shame."
I guess the better way to put it is that if your startup has to resort to paid advertising as the main user acquisition funnel, you probably already lost unless you have ridiculous conversion and LTV on each user.