Microsoft's lucrative new revenue stream? Android.

The irony's enough to make your head explode: Microsoft makes more money from Android than it does Windows Phone.

This according to Citi analyst Walter Pritchard, who says $5 from the purchase price of every HTC Android handset sold ends up in Microsoft's pockets.

Evidently, the terms of the patent licensing deal Microsoft negotiated with HTC over its Android offerings last April included some very lucrative royalties.

Which isn't all that surprising. At the time Microsoft went after HTC, sources close to the company claimed the handset vendor's infringement of its IP was very broad, ranging from the user interface to the guts of the OS itself.

Over at Asymco, Horace Dediu figures HTC has shipped roughly 30 million Android handsets, which works out to about $150 million in Android revenues for Microsoft.

Interestingly, HTC may have gotten off easy. Pritchard says Microsoft is looking for even higher royalties from the other Android handset manufacturers it's pursuing. "Our understanding is that Microsoft is looking for a $7.50 to $12.50 per unit license to settle alleged infringement of Microsoft patents," he writes.