JJ Fake Registered Users
Fake Registered Users is perfect for your new site! It shows, in the same format as the default Joomla format the number of registered users on your site but increased by a constant number. Please also consider Fake Online Users as a complimentary module when considering this.
With this module, you have the option of showing the real or a fake amount of registered users on your site. If you choose a fake amount in the parameters, you can then type in an increase amount which will be added on to the real amount. Perfect little module if you want to make your website look more popular.