Groupon has acquired Pelago, the makers of the Whrrl location-based service/check-in app.

Pelago CEO and co-founder Jeff Holden took to the company blog to announce the news. He says:

You might think at first that this is strange… But it actually makes a ton of sense. Many people think of Groupon as one thing: the inventor of the daily deal. But as it often is in such cases, there is an amazing vision behind the company that goes far beyond what is visible on the surface today. Whrrl’s mission has always been to increase the possibility of adventure in our daily real-world lives, and to that end, we invented an idea economy (with Whrrlbot as its inexhaustible champion!) It turns out that Groupon has a very similar mission, except they approached it by creating a new kind of deal economy.

The mission alignment of the two companies and the fact that we’ve taken very different approaches is a big part of what makes this marriage non-strange, and in fact, very complementary and compelling. And what made this a no-brainer was Groupon’s massive adoption and meteoric growth. The opportunity to take the collective brain power and technology of our two companies and point them at a phenomenon already at huge scale is virtually impossible to refuse.

It doesn’t sound all that strange to me. Clearly, there’s more and more overlap between the location-based services/check-in apps space and the deals space, and with Google and Facebook getting more heavily involved with both of them, I’d expect to see more of acquisitions/partnerships of this nature.

As for Whrrl itself, it’s getting shutdown.

“Think of it as the end of the first act of a long and complex play,” says Holden. “You would be right to expect that the ideas underpinning Whrrl and many of the inventions contained within may reemerge under the Groupon banner.”

So Groupon as a check-in app? Why not.

At ad:tech NY last November, we heard about some interesting things brands were already doing with Whrrl. The Groupon brand should only entice businesses that much more.

Improvements in Groupon’s own service an only help it in the fight against the mounting competition in the deals space with clones and local/vertical-based versions coming out of the woodwork, not to mention Google, Facebook, and the increasingly popular Foursquare.

The good news is that businesses who want to advertise with these types of services are getting more and more options. Perhaps even better news is that many of these options have the potential to attract large audiences.