grower it will pull a blow me when they release it on itunes
The song is a mediocre club song at best with very little Britney in it. It won't have longevity. Also I'm surprise how poorly handled this song has been by Interscope. Jive/RCA would at least put up the song on iTunes simultaneously after the debut.
iTunes is too hectic this week with the new albums' tracks, The Voice songs + AMAs surge. Releasing it now, mid-week would be even more horrid. Next week (preferably Monday) with video premiere Thursday is perfect.
If The Voice songs are surging now, they will do so next week as well.
The only real monster was 'Gagnam Style', the time to release the song is NOW - well, next Monday, mid-week releases are usually awful, and we've had that sad experience with TTWE - before another big song comes and takes iTunes by storm.