I feel there are a few things that drive the traffic to a site most.
1. Offering a quality product
2. Social media like Facebook
3. Updating and Events
4. New Products
5. Word of mouth
First off, if you have a site which promotes a specific product, it should obviously be a quality product which is in demand. Connect your site/blog to a good social media page like Facebook....I know, for some, FB can be a pain in the butt, however its a great vehicle to reach thousands of people in a short period of time. I am constantly updating my website; so it is a good idea to learn how to manage your site YOURSELF, without having to rely on someone else to do it. New products offered from time to time helps as well. Finally, word of mouth....have your site on a card or tell people about it all the time.....They will spread the word. Good Luck!