Do i need a paid domain name for affiliate marketing ?

[Neil]

You do not have any control over any "free" domain as you have to confirm to their detaild T&Cs.

Having your own self-hosted domain you have total control.

The main requirement for successful affiliate marketing is to have a large email address list so all your efforts should be in developing your mail list/lists (and lists should be captured via an autoresponder).

For any worthwhile income from Google Adsense you need tens if not hundreds of websites. Clickbank and PayDotCom are sites for products to market. Also, marketers like myself have their own affiliate management programs for all their products.