There are various ways a tipster can earn money whether that's by being paid by a newspaper (or website) to provide tips, charging a subscription directly to members of their tipping service, through advertising or taking a percentage of any winnings made.
Some people may find value in paid-for tipster services, especially if they are new to betting or don't have the time to do their own research. However, it's important to remember that no tipster service can guarantee a win, and it's still important to bet responsibly and within your means.