86% of site visitors arrive at ExcelCalcs via a direct link or bookmark, 12% are referred from other sites and 2% from search engines. I guess this means that users bookmark the site and new users arrive via an existing user's referral in an email link (thanks for this). We seem to get about 10 to 15 new registrations per day but the growth rate is constant whereas I assumed that growth would be exponential (one user invites two...). I know we have only been up and running for 3 months but does anyone have any ideas how to increase the rate of growth? I hope that we can get a virtuous circle of more users, more contributions, more useful site, more users....