Hello SharonAn affiliate program is a program that pays web sites a commission for promoting their product/service/site.
There is an introductory article about this here:http://www.hits4me.com/arn_money.asp
There is a big directory of affiliate programs (there are thousands to choose from on the Net - but a couple hundred in this directory) - herehttp://www.hits4me.com/income.asp
Now to the links:
When you join an affiliate program, they give you a special link to link to their site. This is an affiliate link.
You are supposed to use affiliate links on your own web site.
Some affiliate programs allow you to use affilate links elsewhere, like ezines or message boards, BUT some do not - and in these cases it is a violation of their rules.
I do not want to be responsible for assisting people break vendors rules, but neither do I want to check the rules of thousands of programs.
A simple, enforceable, rule is therefore required.
I am therefore happy for people to use sigs, or Free Ads (in the right area) for their own web site only - but *not* affiliate links.
One last thing, in my opinion, by not allowing affiliate links, it keeps the tone of the message board more professional - and on topic - as otherwise you tend to get a lot of "dummy" posts which are just excuses to post a link.