If you are looking for a way to boost your initial user base, “beta sites” promoting new products and services are a great way to get a first cohort of users. These users are okay with your offering not being fully polished and it is therefore a great way to test your product before going to market with potentially getting some read long term customers. Betalist.com
Startupli.st
Killerstartups.com
Betapage.co

http://blog.keeping.com/beta-site-hack/