They sold $22MM worth of 3D printers in the last 9 months (3 quarters) - nearly matching their revenue over the previous 3 years, are a household name in the industry, and led by a "rockstar" in the 3d printing world.

So, sounds a lot like "hockeystick" and "hot property" in the software world, no?

They sold for about a 10x multiple of annual revenue. That's not atypical for a startup that's growing quickly.

Sorry, I'm no expert but it seems there's a huge future and a heck of a lot of excitement around 3D printing. Supposedly they've sold 22,000 printers and a deal for $403 million is the equivalent of $18k per unit sold. Given units sell for about $2k, this seems to be a deal focusing heavily on the technology, future and potential rather than the business fundamentals (but, as always, a disclaimer.. I could be wrong ;-)).

It must be for the brand, because Stratasys already has the technology to make 3D printers. It's also defensive, because it's an all stock deal, so the acquired team has to stay at Stratasys for a while (and not be/work for the competition) to make this worth their while.

edit: actually I forgot to do the math. if they sold $44M of stuff already, 10x that for an obviously growing business is a pretty typical exit

Consider also, that Stratasys had no answer to their biggest competitor's (3DSystems) consumer line that's been going gangbusters (Cubify).

I can imagine a world where $403M worth of stock is a good trade for a well-known name, a product line with a large customer base, and profitable consumer sub-unit to compete your biggest competitor, who has the same when you don't.