The consistency of their gross profit (around ~80%) is very impressive.
They are burning a large amount of cash on sales/marketing. Presumably this is forward looking, so it's probably not a big deal (ie upfront costs to get long, multi-year contracts).
Not always the case, especially if you have a large professional server component to your software (& sometimes SaaS). See, for example, Workday > http://www.sec.gov/Archives/edgar/data/1327811/0001193125123...
Gross margin is not the sole metric. However, high gross margin is not a given even at software companies.
- [1] http://kellblog.com/2014/01/21/insight-ventures-periodic-tab...