How can I get some customers for my website?

[Andrea]

You are already using sponsored links that shows on search engines and social networking websites - that's great, but can be a very expensive tool - if you use it as all your marketing and SEO channels.
The calculation is very simple. If your website has been built right, towards conversions, you should have about 4% conversions. Meaning, on about every 100 visitors, you should have 4 conversions. It is very hard to get to such level. Not a lot of websites do that, so if you do 2%, and your margins are right, you're still good.

There are many things you can do "with ten fingers" and without major expenses. Start by registering your website and site map to major directories, such as dmoz.org (the most important, and free!). Without being registered - search engines will never show your site on regular search results.

Start with this, then just search the web for articles about SEO and read a bit. It is not rocket science. Get a username on Google's Webmaster tools. You got all the information and analytical tools for free.