You really should get yourself some paperless business cards guys, hey are you in the know?> this is the cutting edge of technology and ease of networking. Do it!
If you are so much tense about your online business and searching for a solution about how to promote your business through internet, then as far as I know the first thing should be Search Engine. Search Engine allows a website about business, media, social matter everything become successful by attracting the visitors. If you analyze your visitors of your business website then you will find that about to 95% visitors came to your site through search engine. So this search engine can be a great way for promoting your business through internet.
Search engine always like to show the original contents to the visitors. So if you can make original contents at your business site (always keep in mind to avoid copy-pasting formula) then this site will come to visitors through search engine quickly and your site will get enough visitors for buying or selling goods. When you will make good contents at your site then your visitors will feel good and they will stay close to your site. They will never give up visiting to your business site once thy get interests at your site, so try to give the visitors some interest for long term relationship.
Try to be honest as much as possible with your clients. It is very important matter for getting success in the internet marketing and business. You can earn a good sum of money from your visitors by cheating with them, but always keep in mind that you will never get back those visitors to your site and they will post bad comments in many forums or websites about your cheating and google will show that cheating records to the new visitors & then you will not get new visitors to your site and your business will go to hell. So be honest with the visitors as well as the search engine.