Launched with a Series A in 2009, has taken 3 up rounds of funding in the years since, now files for an IPO in 2013, exactly 4 years later. Not only is this a textbook VC-funded startup, it's pretty much a perfect illustration of the ideal trajectory and timeline for a VC-funded startup.

It's started just a couple years ago, made a new business niche, had explosive growth from zero and is going to IPO - a startup by any definition.

Having a web outlet to customers is completely unrelated to that; a niche company selling their stuff to a small handful of large companies and not even having a website can be a perfectly valid startup.