The slow tail
Jakob Nielsen has come up with this concept of slow tail, describing how users often convert to buyers long after their initial visit to a website. The observations are limited to people coming to a site via advertising (so it does not cover people coming through word to mouth for example) but the findings are interesting:
Design Implications
• Users often return to a site multiple times before making their final decision. Your design must therefore support revisitation behavior
• Don’t make premature demands on users who aren’t ready to buy. For example, don’t require registration to read whitepapers or see a demo.
• and much more in the article
