They had $13MM in annual revenue (in 2014) and were acquired for $45MM (~3.5x). Interesting.
It could well be that revenue figure includes "pass through revenue" (aka GMV) as the company isn't public they're not required to follow standard accountancy practices (GAAP, etc.) in reporting revenue.
For startups most of their burn rate tends to be salaries and burn rate tends to be greater than revenue. So assuming they have 20 employees and were break-even and an average revenue per employee of between 150-200k that would imply an actual revenue in 3m-4m range which would be in line with the acquisition figure.