Some recent S-1 filings have included numbers that show the company spending as much as two and half times their annual revenue on sales and marketing alone.

Some argue that this may demonstrates and unsustainable business model, while others would say it's just an early stage startup and that it'll correct itself.

Splunk's been public for quite a while and is the same way. In fact, even eliminating their entire R&D wouldn't result in them being profitable.