Katy Perry just hit over 1,000 plays on my last.fm count (now my second most played artist, passing Gaga at around 600 plays)... bitch is coming for Ke$ha's wig.
When 'ARTPOP' drops, I'll see how they fare. 'PRISM' has great replay-ability, though... and the second half is really growing more and more on me track by track, too. (I found myself bopping along to "Love Me" and "This Moment" more than I did at first, today.)
When K$ releases her new album though... I'm thinking she's going to reach 2,000 plays in less than one week (currently at around 1,500).
