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Music streaming service Jango, which is six million monthly listeners strong, launched a program that enables labels and artists to buy "plays" on its site.

For as little as $30, Jango Airplay lets bands, for example, buy 1,000 plays on Jango. When artists buy a package, they have the option of choosing other artists upon alongside which their music may be recommended.

Each song gives listeners the opportunity to buy the track on Amazon or iTunes, making it possible to earn that money back if the song fares well. Popular songs — those with 50 positive ratings or more — also get airtime in addition to the time purchased.

In addition to letting buyers decide which artists to affiliate themselves with, Jango Airplay also targets songs to specific stations. For example, a heavy metal band can buy plays on a Metallica station, versus a Bob Dylan station. This maximizes the likelihood that plays will be spent on users most likely to enjoy — and thus purchase — the music.

As a point of contention, however, , TechCrunch points out the music is not clearly labeled as sponsored material; it's instead marked "emerging artist" content.

"It is an ad, and it should be clearly marked as such," the tech blog wrote, hastening to add, "I am okay with this sort of promotion as long as [it] is targeted to my listening preferences."