Pay-by-bitcoin will be a new payment option for invoices, thanks to a free service from Intuit announced today. Small businesses who use QuickBooks Online can register for a wallet with Coinbase and link it to their account. Intuit's new PayByCoin service then allows customers to pay with bitcoin (in addition to all the normal ways) and the business records the transaction as usual. How many people will use the service? It will depend on how many existing customers already have quantities of bitcoin laying around to spend, but it's still a move that makes it just a little bit easier for businesses to accept the cryptocurrency.