This is often characterized as an investment, where the money Bezos paid is accessible by the company to do company things - but this seems to be private sale of shares from founders to Bezos. I don't think the company got any money out of Bezos' check - think the founders got it to their personal accounts. That would not qualify as an investment in the sense we're talking about, no?
Investment seems like the right word to me. It wasn't fundraising for the company, though. It was the owners selling a portion of it to hedge the risk that it might fail (according to the link article). That implies to me that they kept the money for themselves rather than re-investing it in the business, at least at the time.
They're also claiming it was a "no-control stake", so not quite the same deal.
That kind of investment opportunity that says "if you trust us buy shares in our future, but you just get to come along for the ride and get X% of profits" seems different enough from VC investing to have its own name, don't know if it already has one.
