When it comes to building a website, one of the key factors in establishing a sizable user base is your site's ability to 'go viral'. While there isn't any magic secret to accomplishing this, there are a few things that can help - namely, making it as easy as possible for your users to sign up, and helping them invite their friends. But this is easier said than done, and determining exactly how to implement these seemingly obvious steps can play a huge role in a site's success. Product Planner, a new site that launched this week, is looking to help companies tackle this issue. The site has visually mapped out over 100 'flows' that visually depict exactly how many of the web's most popular services operate. For example, Gmail's signup flow consists of inviting a vistitor to first click 'Sign Up for Gmail', followed by a form asking for information, and finally a confirmation button that says 'show me my account'. It may sound simple, but being able to see each of these side by side can be invaluable when it comes to actually building your site.