http://www.digg.com/ PR 8 http://del.icio.us/ PR 8 http://www.furl.net/ PR 8 http://technorati.com/ PR 8 http://myweb2.search.yahoo.com/ PR 7 http://reddit.com/ PR 7 http://www.fark.com/ PR 7 http://www.43things.com/ PR 7 http://www.mister-wong.de/ PR 7 http://de.lirio.us/ PR 7 http://www.newsvine.com/ PR 7 http://www.blogmarks.net/ PR 6 http://ma.gnolia.com/ PR 7 http://www.simpy.com/ PR 7 some bookmarking sites for u !
At first i have to know what types of product you have then by this situation i suggest to you the good site. But always I prefer eBay. eBay is the best marketing site in the world for any kind of product. And its payment system is really flexible.
Most of the people use FACEBOOK and TWITTER for their business development online. But Google Adwords is one of the best thing also.
Facebook is the best marketing site, there are many peoples and companies are using this site for marketing.
I would strongly like to say that in the modern age facebook is one of the marketing social networking site. Facebook is Facebook. By creating business page on that,doing some updation,adding good photos,good quality video in it you can promote your site. And this is how you can earn a lot of money.
I believe social networking websites are great help for you to gain popularity of your website, and they are natural backlinks.