Pokki, a company and service that is betting on the desktop computing environment of Windows, today announced that it has crossed the 1.5 million download mark on the Windows 8 operating system.

That figure, impressive though it is given the youth of Windows 8, matters as Pokki in effect replaces the removed ‘Start Button,’ an iconic piece of Windows user interface that was removed in favor of the new Star Screen in Windows 8. Thus, downloads of Pokki can be seen as a response to Windows 8’s user interface changes, a mild repudiation if you will.

The 1.5 million figure is all the more noteworthy when you compare it to the firm’s last reported milestone: 500,000 downloads on December 20th, or a mere 26 days past. On a daily basis, that equals more than 38,000 downloads daily.

Microsoft has now sold more than 60 million licences of Windows 8, not all of which are on active PCs yet. However, assuming that they were – to tilt this comparison into a more Microsoft-friendly ratio – Pokki has been downloaded on around 2.5% of all Windows 8 PCs. That’s non-trivial, and a bit embarrassing.

Ironically, the openness of the Windows 8, non-ARM, platform creates the space for Pokki to cause its mischief. This brings us to the interface updates that the company is rolling out today:

Pokki, in this new iteration, has done something that will grit Microsoft’s mouth a bit: it has changed the icon in the lower left from its own trademark acorn, into what could pass for an official Windows button on Windows 8. Also in the update are tweaks to the layout of the service, helping uses to access their apps and the like more quickly.

At 1.5 million downloads thus far, Pokki is likely to capture enough of the Windows 8 market to act as a second marketplace for app developers looking to target the platform. For a more granular take on why Pokki is focusing on the market that it is, and why, this previous article has the breakdown.

Pokki’s bet that Windows 8 would be key with its growth was a seemingly correct one. Now what the company will do with the users it has accumulated becomes the key question.

Top Image Credit: Brian Snelson

Read next: Large-display smartphone shipments predicted to more than double, passing 60 million units in 2013