Slideshare acquired by LinkedIn

Don't you mean:

$119Millon Sale price / 3Millon Funding = CRAZY RETURN!

Hard to say based on what information is around, but part of it should most likely be justified from Instagram valuation for Facebook: no new feature, or strikingly innovative know-how, but a proven ability to innovate from the de-facto key feature and turn that into a sustainable network effect.

I sell what is essentially presentations (teacher & consultant data analyst); SlideShare is very far from what I'd like to have, but the only service where doing so makes sense. They could easily set up better presentation features (voice over, animations, structure) or insist on the selling tools (even the tiniest fraction of the teaching/conferencing/consulting business at large is huge) but they already have the core asset: most though-leaders are subscribed, and their account actively follows the accounts of people relevant to them. Compared to Scribd, who has the selling and control tool in place, but enrages users by blocking pdf exchange for no good reason, they seem to win.

LinkedIn is trying to move towards learning and showing your expertise at a more regular rate than job switches, and SlideShare has the best asset for that.

The quality of the Team and a pretext to talk about interaction design won't hurt, either.