Why does no one get that it takes lots of headcount to do ads and sales? According to another HN commenter they were pulling $170m in revenue and growing at a 30% rate. They had job listing ads from literally all the major companies and you need people to help close those deals.

People seem to forget that you need big sales teams to build a huge advertising business. Even companies like Google with self serve advertising products have 1000s of employees because closing big advertising deals with corporations requires big sales and operations teams.

Acquirer is paying for the community, not the easy to replicate tech. There were lots of image sharing apps, but only one Instagram.

What community though? There are three groups that use the site - employers, employees who want to vent and job seekers.

The first are captive, the second only allowed to post once per year, and the third is ideally a very temporary situation.

It's hardly comparable to a social network, or even other review sites (which can cater for enthusiasts)

There is gold in what you just wrote. These groups had a need to connect socially, anonymously, and in a way that is urgent and temporary.

I think you've just answered your own question. Post limits don't change the value of the information submitted, not does people looking for work change the value of their talent to potential employers.

It's not comparable to a social network because it is a social network: people and relationships and they're nodes and vertices on a social graph.