Here are a couple of methods to increase your traffic flow without having to spend a cent.
Online forums and online communities
The notable thing about forums and online communities is that you can target only those people that fit the particular demographic you're looking for. There are online communities for about any niche where you can discuss topics about the niche you represent.
Online communities and forums are a great way for you to build a reputation for yourself and your company. Write about what you know and impress them with your range of expertise about the subject. As you do that, you will build a reputation and build trust with the people in your expertise and knowledge.
Trading links with other sites
You don’t have to spend a cent when trading links. All you have to do is to come to agreement with another webmaster. When exchanging links, the efforts both sites put forth will benefit both sites. Any traffic that goes to one site could possibly click on the link of the other site and visit that site as well. This works especially well when both sites emphasize the same niche.
Each of these methods can drive more traffic to your site for no cost to you. It will take some effort and a few hours of time. Learn everything that you can about the methods described here and you'll soon have a site with great traffic flow without the usual costs.