The company said this week it will halt the planned rollout of Kin One and Kin Two phones beyond the US, less than two months after Verizon Wireless started selling them.
Microsoft unveiled the two Kin phones in April, though they were widely anticipated after photos and details appeared on blogs last year.
Kin One is an unusual, stubby little thing, while Kin Two looks more like a standard cell phone designed for heavy text messaging.
Both have touch screens and slide-out keyboards, and were marketed to appeal to a younger crowd that wanted to share web snippets, photos and video with friends. Both have Microsoft's Zune media player software built in.
For a second, the Kin was everywhere, including prominent product placement in an episode of The CW Network's Gossip Girl teen drama.
But from the start, the Kin didn't seem to fit into Microsoft's mobile family.
The phones marked a major switch in strategy for Microsoft. Before the Kin, the company provided phone operating software to a large array of hardware makers.
The Kin was manufactured by Sharp, but Microsoft controlled the hardware design, and by doing so would compete with its partners.
The timing of the Kin's arrival was also off. Microsoft had just announced an overhaul of its smart phone system, Windows Phone 7, that bore little resemblance to the Kin.
And during the years Kin was said to be in development, smart phones grew more sophisticated.
Kin doesn't have extra "apps" for download or a GPS mapping function. Yet the required $30 monthly data plan for Kin was identical to plans sold with more advanced smart phones.
Neither Microsoft nor Verizon Wireless would say how many Kin phones have been sold.
Earlier this week, Verizon cut the price of Kin One and Kin Two to $30 and $50, from $50 and $100, respectively.
Now, Microsoft says it will not sell the phones in Europe this fall as planned.
In a statement, the company said it had decided to focus on the launch of the Windows Phone 7 software. The Kin team and its technology are being folded into the Windows Phone unit.
Verizon Wireless spokeswoman Brenda Raney said in an email "the Kin is still an important part of our portfolio."
Neither company would say whether Microsoft will produce more Kins once existing stock sells out.
