Google's load balancer offering doesn't need to prewarmed was the main point. Its a fair point, having to prewarn ELBs isn't exactly fun, form takes about 10 minutes to fill out. If you're doing TV ads, lots of stuff is last minute. You can prewarm it yourself by throwing artificial traffic at it but you always risk just taking down the ELB if you ramp up to fast. Weird things happen to ELBs if you spike them with big bursts of traffic, one of service providers had 24 hour backlog of web hooks that they sent out all at once. It caused our ELB to fail all the instances even if we brought up new ones. Also during load you can get other sites to show up on your ELB. Had asp.net error page show up on ours. We run rails. Wish amazon would scale up ELBs instances based on the number instances you have behind it using the ratio calculated on past usage.