If you can send users to an advertiser’s website by placing a banner on your own website or writing an article containing text links, posting an update on your social media profile etc. then you can become an Affiliate! If the users you sent then convert to actions like sales or registrations then you will receive commission for these actions.
Example: An online travel agent offers 5% commission for every air ticket booking that takes place on their website. You own a travel forum and place banners of that travel agent on your forum. For every user that clicks on the banners and then books an air ticket, you will receive a 5% commission on the value of the ticket the user booked!
See our affiliate programme catalogue and find the programme that best suits your own website.