The acquisition price of $1.5 billion is pretty eye-popping.
I saw that 48% of that is in LinkedIn stock, which always makes me suspicious about the actual value of the deal, so I just looked at that, too: LinkedIn stock has roughly doubled in price this year. Maybe getting around $750 million in stock ain't so bad.
Looking at the stock trade as part of it, I'd guess this is more about Linked-In making themselves look good as an acquisition themselves, than it was about adding a relevant user community and professional talent pool "hook" to Linked-In. Or it's just my week to be extra skeptical.