A Sales Funnel is a well thought-out pattern of follow-up sequences, product upgrades, and offers that are designed to maximize the amount of income that you can earn from each visitor or buyer to your site.
Most sales funnels start with giving away a small bribe in exchange for people's information. After that, you can maximize the opportunity to unveil to your site visitor all the services/products you provide.
Not having a sales funnel means you are leaving money on the table, or even worse yet… you are not being effective in converting your site visitor into buyers