Here's the facts as I see them: Crunchbase says Hunch started in September of 2007 and had 23 employees on LinkedIn when they exited. (TechCrunch calls it a 20-person team, so I'm presuming that's all the employees.) They've gotten $19.2m in funding, let's just say $20m. TechCrunch claims the sale was "around" $80m.
So what does the breakdown look like? Who gets what? What are the likely investor terms?
My totally naive guess would be that the investors got at least a 1x liquidation preference, maybe more. I mean, did Hunch have any revenue? So there was at most $40m to go around to the people at the company. Of course, most of that probably went to the founders. Would maybe 20% of that have gone to the 20-ish employees? So naively pretending that each of the 20-ish employees got 1% for four years, did they each end up with an extra $100k/year? What's the likely distribution of shares among employees?
What are the transaction costs (lawyers, taxes, etc.) for this sort of acquisition? How long will the employees have to be at eBay to get their earn-out, and will that earn-out be in addition to their common stock in Hunch? Will they end up being paid less to work for eBay during their earn-out than if they were on the open market?
Of course, their are many other reasons to do a deal like this (passion for improving eBay's recommendations, for example), but let's ignore that for now.