>has been doing with all their raised VC

VC money is not the intent of this program. Airbnb is trying to capitalize on the hundreds of millions of dollars in customer deposits they hold every day. Instead of letting this money sit in a bank account collecting minimal interest, why not invest some of it in a money market fund?

If Airbnb plays their cards right, in a few years they have the option to remove platform fees entirely and still be profitable just from their market investments. Imagine that. They just need to hold on to customer money as long as possible, which I believe they already do (I'd estimate they sit on money for 2+ weeks on average).

Paypal was a major innovator these techniques over a decade ago.