Typically, affiliate programs delay payment long enough to minimize fraud. How long that is in your case is of course your decision, but I would say at least a month. When I ran my own affiliate program back when I was a host, I did recurring commissions of 10%, because I thought that best aligned everyone's long-term interests. But the standard in the hosting industry is not to do recurring affiliate commissions; instead, they do larger one-time commissions. Especially in that case, you must wait long enough so that you don't pay out, say, 100% of a year's revenue in commission when the customer only pays for the first month and then backs out (legally or fraudulently).