Hi Assaf,
I can tell you that for our site
Posicionamiento en buscadores, primeros puestos en buscadores, SEO y SEM producing quality contents has proved to be the most effective way for attracting qualified traffic. We started by publishing specialized articles in our website and then had several Google Alerts scan the web to find which other websites were publishing them. When we found them in other sites, we e-mailed them and asked them to keep our credit line with live links pointing to our web. Now, dozens of websites publish our articles and keep links pointing to our site. These websites bring qualified traffic and increase our page rank in lots of keyword combinations that are important for us. For example, if you search for
"Marketing inmobiliario en Internet" in Google, you can see that my web and my articles in other sites are in top positions. Just a suggestion! Good luck.
Fernando