Who needs web traffic?
Obtaining traffic may or may not really be that important to you. I have met some bloggers that really didn't care how many people (volume wise) visited their blog. Generally you really care about traffic levels when you are running an eCommerce site or a business site for the real world. Some businesses that don't rely heavily on online advertising don't seem to mind low traffic levels as well.
How and where to obtain web traffic (the usual suspects)
If you decide that you will need a steady flow of traffic and you don't feel like paying for additional advertising then you need to make sure your content is properly coded for search engines and make sure you place well (SERPS). For more details on this be sure to download my free eBook.
The not-so usual suspects
Over the past few years I have found an interesting source of traffic that is often overlooked. This source is web widgets and iGoogle gadgets. Google gadgets get a good deal of traffic and can be an additional source of traffic for no additional cost.