There are two types of real visitors that you can get to your web pages. These are called targetted visitors (those who you know have an interest in what your page is about) and un-targetted where the people "visiting" your page may or may not have an interest in the content.
We can further subdivide the targetted traffic into two groups - those you pay to get and those who find your content through other means. There is no equivalent split for un-targetted traffic since you have to pay for all that sort of traffic in one way or another as those who find your page without your paying to get them there all qualify as targetted traffic.
Let's work through these three types of traffic starting with the least useful type and progressing toward to most useful and see how we might obtain such traffic and what that traffic might be worth.
There are a couple of ways to get un-targetted traffic. One way is to buy it and the other is to join some form of exchange program where those who visit your site see some other site along with yours and those who visit other sites in the program see your site along with the one they were visiting. Either of these methods will serve to increase the number of visitors that you get to your web pages and will increase the bandwidth that your site uses. Regardless of how you pay for the un-targetted traffic the vast majority of these visitors will only see your page for as long as it takes for them to hit the close button. Only an extremely small percentage of this traffic will have any interest in your page at all. Such traffic is in most instances not worth having even if you could find a way to get it without paying for it sinceyou are basically using up bandwidth for no purpose.
There is a short one word description that can be applied to targetted traffic that you pay for. It is called advertising and there are three basic models that the web uses for how you pay for it. The least targetted payment method is called Pay Per View and involves your paying for each time someone sees your ad. This is still targetted advertising provided that some mechanism is on place to ensure that the ads only appear to those who are known to be interested in what is advertised (as is the case with context sensitive advertising).
Pay Per Click is a more targetted form of advertising in that it is still targetted even where the advertising is not context sensitive because you only pay when people click on the link and actually visit your site as a result.
The third sort of advertising involves paying a commission on sales and is even more targetted in that those you pay for have not only got an interest in what your page is about, they are interested enough to actually buy from you.
The only difference between paid targetted visitors and unpaid targetted visitors is that you don't need to pay money for those in the latter group. Basically that means that someone else is paying to advertise your page for you. For example search engines will list your pages in their search results for those subjects for which your content is a closely targetted match. They do this in order to provide a useful service to their visitors so as to get more targetted traffic for themselves. They will display contextual paid advertising alongside the other results and will make sufficient money from that advertising to make having the pages of search results there well worth their while.
This article written by Stephen Chapman, Felgall Pty Ltd.