So digital sales are estimated to be 1,955 in the past 24 hours. Since the program tracking sales doesn't account for the fact that the song has only actually been out for 3 hours, a more accurate tentative estimate would be about 16k so far. Depending on the next few updates that estimate could prove to be low, too.
Which is why I did some of my own calculations to account for that.
They only measure based on a 24 hour scale, so any big debuts like this are whacked out by their stupid system (thanks to iTunes being a rolling chart).