How can I get users on my website?

[sroca]

I have developed a website and gathered Facebook and twitter followers for it. Everyone I go show the website to or explain how it works will tell me it's awesome, it looks great, etc. But not many of them are registering on it eventhough it's very simple. How can I get more people to actually register on the site and use it so that it can fill with more content? I've made an indiegogo project for it and I am making a video. How else could I promote it?
And also I have done seo on it

[Josie]

You have asked a great question that requires a multi-layered answer. What you are saying is you need online marketing. This sort of marketing is accomplished with an overarching plan for your site that places different focuses or emphasis on the following components:

Content marketing (original ideas)
Social marketing (interaction and contests)
e-mail marketing
Pay Per Click
Linkbuilding
Public Relations

and anything else you can figure out.

Have you visited Moz? That is a great launching pad. You are entering into a whole world that is running behind all great sites.

[Darren Ebona]

Conversion my friend, conversion. Conversion is the act of converting site visitors into customers, loyal readers, SUBSCRIBERS, etc. You may have good content, done good SEO, advertised it on the web, shared it on social-media or forums but your site's visitors are not doing what you expected them to do then your website is still, pardon the term, a fail because it is not converting visitors to, in your case, sign-ups. Search "Neil Patel" or "Quicksprout" on Google and you will hit the "Pandora's box" of conversion rate optimization.

[Harendra]

Try http://www.40Billion.com They do an excellent job of promoting product in most cost effective way.