Airbnb is a cash-flow machine and a great stock to own.

A chart circulated on Wednesday shows Airbnb rental revenue falling in some major U.S. cities, even as a separate set of data took issue with that.

London property and rooms rented through Airbnb can generate more than £6,600 ($7,970) of revenue in one month, according to research firm Airdna which specialises in Airbnb data. The below chart ...