Investing.com - Square (NYSE:SQ) CEO Jack Dorsey has incorporated bitcoin into the business of his high-flying mobile payments company. Now he's making bold predictions about its future use.Dorsey, who's also CEO of Twitter, thinks bitcoin will become "the single currency of the Internet" within the next 10 years, according to a report in the British newspaper The Times.Dorsey says bitcoin isn't capable of being an "effective currency" at the moment because it is "slow and costly", and companies like Square need to help make the currency more widely accepted.Square has allowed users to buy and sell bitcoin on its Cash app since January and is looking at using the digital coin in other services.Dorsey is also a seed investor in Lightning Labs, which is developing a software to make bitcoin transactions faster and cheaper.