The most popular dating app of the last few years may be the author of its own downfall.

Tinder, which launched in 2013 and has grown exponentially in popularity ever since, has been testing a subscription service in Europe and the results have not been good.

Tinder’s immense popularity is from the almost game-like ease of use that requires only a right screen swipe to express approval of a potential date (or a left swipe to disapprove). Users also don’t have to painstakingly set up a profile to begin being matched.

The problem is that subscribers to the new Tinder Plus will have unlimited swipes, while non-subscribing users will see their swipes limited to an amount which is still to be determined. As it currently stands, all users have unlimited swipes and this cap on swipes is causing the outrage in Europe.

Tinder has dominated the US dating app market, accounting for over 80% of total app sessions, according to 7PARK Data. This far outpaces second place app OK Cupid by over 70 percentage points. Additionally, Tinder has continuously been in the top 250 of the US App Store and has seen its users steadily grow over the last three years.

Insider Take:

Why would a successful app like Tinder mess with its proven model by instituting a subscription level? The answer is money, as it often is. Many people think of Tinder as a standalone app, but in reality it is owned by IAC, parent company of Match.com and OK Cupid. The stunning popularity of the app probably exceeded even their most optimistic expectations, and now they are instituting a paid subscription option to cash in. If they succeed, it will highlight once again the efficacy of the subscription model for dating sites. If they fail, the lesson will be the one given to Coca-Cola in the 1980’s: “If it ain’t broke, don’t fix it.”