How to promote website without advertisement?
In social networking sites?
Search engine optimization.
I think Advertisement is one of the most sorted way to "promote" any product. Second is do something unbelievable with your website so that media will get attracted. The rest will done by them.
Having a unique and informative content is a great way to promote your web site. Readers will find it helpful and could refer to friends. Words of mouth is an effective way to promote.