I don't think really. Based on some discussion, it seems they are more adding a pile of new servers everyday, and they also seem to do a very good job at automating their process etc.
Yes, 1000 servers translates to roughly 40 racks and you'd better have a team of sysadmins to babysit them.
Imho that doesn't have much to do with hiring 40 perl developers in one fellow swoop, though.
It's not what a startup would do, correct, but they are swimming in money and this practice apparently gets them even more.