This document discusses how to earn supplemental income, or "beer money", through affiliate programs and ads on a travel blog. It explains basic terminology like revenue per click/impression and affiliate commissions. Typical earnings are estimated to be a few pence per click or around 5% commission. Maximizing visitors through links from other sites can increase earnings from tens to hundreds of pounds per month, depending on effort. Resources for programs like Google AdSense and Amazon Associates are provided.