It is not true that the best way to increase traffic is to attract as many new visitors as possible. They will come for a few seconds and go.
Even if a visitor bookmarks you, he is unlikely to ever return once she leaves. (Check your own Bookmarks or Favorites list to see what I mean!). No profit. The site is not popular. But when they come again, this means that your site is really needed.

Why is it important to attract people to come again?
There are many reasons why you would want your visitors to come back to your pages. If you sell banner advertising space, you can easily calculate that a person who comes to your site, looks at five pages and then returns ten times within the next year and checks out an average of two pages per visit is four times as valuable to you than one who reads five pages but forgets all about you after leaving.
Owners of online stores benefit from an increase in return traffic as well, because in many cases it takes more than one visit to make the sale. The visitor might not need your product right now, but he is likely to buy from you when the time is right.
Another advantage that arises from such visitor loyalty is that those who regularly visit your site often mention it to their friends, family and colleagues. This can easily create a so-called traffic virus, which is born when people tell about you to their acquaintances, who then spread the word to their own acquaintances and so on. While it might not sound like a very big deal, word-of-mouth is the primary source of traffic for many larger sites and the reason they have become what they are today.
What do you need to do to get people to keep returning to your pages?
The first and main thing is to have high quality content. And to make people trust you. To make them believe that you are a real expert in your niche.
Get links to your site.
Get people with complimentary sites to link to yours. Links lead to clicks onto your website and help to improve your search engine rankings.
Get published.
Write articles for publication on other websites. The author profile will link to your site. The article will show that you`re an expert.
Publish yourself.
Write articles for your own site regularly. This will help you to win on the search engines and gives your visitors a reason to come back over and over.
Feedback
You need to talk with your visitors. It can be some forum, blog or even newsletter but it is very important for visitors to be able to ask questions and receive answers. You never can see the faces of your visitors, but you are to persuade them that your face and your site are the most relevant for them. Ask for reviews.
Ask for reviews of your self-published articles on other webmasters` websites. Ask for reviews of your website, your products, your software, your services. These will usually include links to your articles.