Spotify isn't profitable quite yet, but with 10 million paid subscribers, the company is likely closer than anyone else in the on-demand music space to breaking even. You could attribute the company's success to a variety of things, from its extensive music collection to its fleet of apps for almost every platform, but I think another side of Spotify's business deserves a bit more credit: the increasing number of apps, gadgets, services, and even cars that plug directly into Spotify. The latest is a hard-wired integration with Djay, one of the most popular DJ-ing apps, which lets you stream two tracks from Spotify simultaneously and mix between them in real-time.

The integration gives DJs access to a library of 20 million tracks, where before, they would have only had access to their local iTunes library or to a crate of vinyls. You unfortunately can't record and share your mixes inside the app due to licensing restrictions, but you can share the sets you've created on Facebook and Twitter as Spotify playlists. The app's coolest new feature is Match, which uses data from Spotify and The Echo Nest (a recent Spotify acquisition) to cue up tracks that will mix well with the current song based on beats per minute, key, and other factors.

"Today, there's been a clear shift that more and more people don't have music or media on their devices — they use iTunes in the Cloud, or subscription services like Spotify," says Karim Morsy, the creator of Djay. "Spotify integration has been one of our top requests." As music consumption moves towards streaming services, I think Spotify has a more interesting opportunity than simply becoming the iTunes for the streaming age, as many have dubbed it. Where hundreds of accessories "Made for iPod" once made iPods that much more appealing, I think we're about to see even more services and apps that are made for Spotify, or made for your other favorite music services.