Make a sale and you get paid once; set up a subscription sales model and you get paid every month. The drawback: you're going to have to save financial data for your customers and that can create privacy issues.
First the positive: Subscription business models are booming for online businesses. Rather than selling a customer something once, the subscription model guarantees that same sale once a month without any extra work.
Setting up a subscription model for items that are necessary or that customers are passionate about can mean more sales and better relationships with your clients.
But to keep collecting payment you have to find a way to save customers' financial data.