It takes extra work but the reasoning behind it is solid. A landing page is the first thing someone sees after clicking your ad. If your ad promises something specific but the page it leads to is just your general homepage, the visitor gets confused and leaves within seconds. When the page matches exactly what the ad said, people feel like they are in the right place and are more likely to stay and do something. Separate pages also make it much easier to track which ad is actually driving results. Do you think most small businesses fully understand how much a landing page affects whether an ad actually works?