According to The New York Times, Best Buy is giving those who purchased HD DVD players from them before February 23rd (the day Toshiba announced the end of the format) a $50 Best Buy gift card. The NYTimes summarizes the program nicely:
The Best Buy cards, which will not expire, will be sent automatically to most customers who purchased HD DVD hardware by February 23, when Toshiba announced that it was abandoning the format. Best Buy’s list includes those who belong to their rewards program, bought extended warranties, or purchased the machine on its Web site. Others need to show proof of purchase to get their cards.
Basically, if Best Buy knows who you are they’ll send you the card automatically. Otherwise you’re going to have to go in and claim it, with proof of purchase. Best Buy sold HD DVD players to over 200,000 customers, so if everyone eligible claims their card this could cost them over $10 million. But it is clearly a solid PR move to help those who might feel burned by picking the loser in the format war take a more favorable view of Best Buy. And, since the card is only good at Best Buy, it will help encourage them to come back in and buy more – perhaps a Blu-ray player.