Sales and marketing are roughly 1-to-1 with revenue growth, and the spent over $100m in 2014 to make $63m in revenue. I don't find these metrics particularly encouraging. Now this is a SaaS business where you're betting on LTV - but these metrics are tough imho.
While I agree regarding the revenue growth, as someone who uses the service heavily in production, there is significant lock-in and the product is great value. If they continue to innovate this could be a good bet (one i will consider making personally)
I just find its one of those products that the more you use it the more you simply cannot live without it. I could see someone copying the product, but personally I'd probably continue with New Relic unless the price difference was significant.
I found their sales team incredibly pushing, bordering on aggressive.
I was happy enough on a free plan and they were trying to get me to go to the next tier up which was $200 a month. Must have received about 10 emails from them trying to 'work out a deal'. I would have just been happy with some pricing in the middle but the jump was far too high. Anyway whole thing left a bad taste in the mouth.