Its funny that lists of top 50 startups basically only include consumer/social startups. Square is the largest business on that list that could be considered B2B, but even then its about as consumer-facing as a B2B company can be. After that you have to wait to Echo in #32, though while selling B2B, its end users are all consumers.

I remember 2010 as the peak of time when all the excitement was about mobile/social/location startups, so I guess its no surprise that a list then only includes that kind of company. SaaS (esp B2B SaaS) [1], is basically completely absent from the list.

I see people making the mistake of thinking consumer companies are the only companies out there, but hopefully people will start to see that SaaS companies are worth discussing in these lists. Investors and public markets are already in love with SaaS, so maybe the 2014 list will be more interesting.

[1] Before any pedants say that all of these are SaaS because the software is hosted and thus delivered as a service, please don't. SaaS as a business model means paying for a service via a recurring revenue model.