There are a lot of services out there which offer "affiliate marketing", i.e. you refer your friends (who you know have certain needs) to certain products or services, and when they buy them, you earn referral commissions.
For example, do you know programmers? Make money by referring them to Codelicensing.com:
If you don’t receive the email in the next 2 minutes please check your junk folder, and add [email protected] to your safe sender list.