The marketing funnel is a tool that helps marketers to understand their customers and make decisions. The TOFU marketing funnel is the traditional funnel where the first touchpoint is the website. The MOFU marketing funnel is where the first touchpoint is an online ad. The BOFU marketing funnel is where the first touchpoint is a mobile ad. The TOFU and MOFU funnels are more common in digital advertising, while BOFU tends to be more popular in mobile advertising.