When choosing between immediate profitability or faster growth, the smart decision is typically faster growth, as that leads to much greater profits down the road.
Remember when the HN crowd thought that Facebook could never be profitable because they were making the same tradeoff?
Yes and Facebook is probably one of the only of those who started with growth rather than looking for profit that has in fact become profitable. But they still haven't managed to make the amount of money back that was invested in them.
According to CrunchBase, facebook has raised roughly $2.1B totally (including their IPO, which accounted for $1.5B of that). [0]
In 2014, facebook totalled roughly $3B net income [1]. So they made dramatically more money back in the last year than they raised totally and will probably continue to do so.
Multi billion dollar startups are so rare that trying to mimic them is a fools errand. It's the same logic from people that say, "Bill Gates dropped out of college, and look how rich he is!"
Remember when the HN crowd thought that Facebook could never be profitable because they were making the same tradeoff?