Those supply issues have reportedly been ironed out now, but HTC is still feeling the guilt of not delivering its One on time and has decided to reward those who have placed their orders on the first days with a $25 Google Play gift card.
Check your email to see if you are amont the lucky ones. In the letter, HTC says:
It’s great to see HTC caring about its customers, especially in tough times for the company like these. The HTC One has been a relative success so far, recording 5 million sales in around a month, and hopefully giving HTC that needed momentum to get it out of the gutter.
source: Android Central Forums