Here's an interesting problem to have. What happens when your company starts scaling out in a matter of hours or days to traffic levels that would have normally taken years? That's the situation that music site www.iLike.com
(formerly GarageBand) faced after they launched May 23. They started getting tens of thousands of new users hourly through Facebook and eventually went from a million users to over 6 million in and the space of a few weeks, begging and borrowing more servers from VCs to keep things going. They reached an audience size in weeks that it took Rhapsody years to achieve. Now that's a fast pace of scale out! They announced on June 11 that they are now the fastest growing music website. Heck, its probably worth making iLike our honorary 13th example in our 12 Days of Scale-Out feature on our web site.
The company President is ex-Microsoft VP Hadi Partovi who was previously General Manager of the MSN portal. However, like most new web-based startups, iLike is built on the open source LAMP stack. While it's possible that a Microsoft-only stack might have been able to scale, I would think the cost would be prohibitive. Even if you just assume a nominal fee like $5k per server times 150 servers, that's $750,000, which is not chump change --even to ex-Microsoft millionaires.