Congrats to the SO team. That said, I'm struggling to understand how/why a they could possibly need to raise now a total of $153MM.

All the content is community generated so there's no costs there.

The core Exchange product is extremely templatized and I would assume be quite scale-able to spin-up as they need additional ones.

I don't believe they have much in the form of paid outbound marketing initiatives.

I'm assuming that I'm completely missing something here. Educate me. ;)