One of the first Web 2.0 style sites was Amazon and it's ability to allow users to post book reviews. This was and is very popular with Amazon visitors. The visitor has an experience that mimics real life. Average people are commenting on books that we are considering purchasing. We tend to trust a book review from someone we know or meet just because we feel it is unbiased. They are not necessarily trying to sell us anything.

The new web 2.0 experience is very much user-driven. Sites like YouTube, Flikr, Technorati and Digg are essentially controlled by the users. They create the content and decide how it's displayed by ranking it. The articles, pictures and videos that are voted the most popular receive greater exposure.

Wikipedia, an online encyclopedia is created by it's users. The entries are entirely written by the general public.

Blogs are the backbone of Web 2.0. Blogs have been around for a while. At their simplest a blog is just an online diary where entries are displayed in reverse date order, with the newest at the top.

Blogs were decentralized from their very beginning. Blogs are a great example of how emerging voices are not only being heard but amplified. Blog postings, typically updated daily, can also include images, photos, links, video and audio.

Then of course, there are the social networking sites like Facebook and MySpace. These are immense web communities with hundreds of millions of users. They allow subscribers to create web spaces where they can share their thoughts, music, videos and pictures. People can become your friends and then stay in contact with all your various activities.

There are also sites like del.icio.us, that allow you to bookmark your favorite sites and share those bookmarks with others.

These types of sites have become incredibly popular. The users of these sites now control the content. This creates a very rich and ever-changing experience that is very engaging.

For online marketers web 2.0 sites offer a new way of generating traffic. This way of traffic generation may seem a bit hit and miss compared to traditional SEO (search-engine optimization) but in reality it is very effective. The main difference between traditional SEO and web 2.0 is that the results can be almost immediate. For example, if you were to post an article (or a link to an article be exact) on Digg and the users of Digg found the article interesting, they could vote it up in the rankings. If your article showed up on the main page your site could receive hundreds of thousands of visits. This could all happen in a matter of hours. Try getting that kind of response from a search engine. Google would probably take a month or more to even index the page.

At the same time this traffic will probably be short lived. However, you would still have a link from Digg pointing to your site, which in traditional SEO is valuable and would help your search engine ranking.

Squidoo is another site that provides both traditional SEO benefits and web 2.0 opportunities. Squidoo allows one to create a simple web page using modular tools. You can use this page to link to your other sites and Google seems to love links from Squidoo pages. You can have as many Squidoo pages as you like and can use keywords in naming your page. Squidoo pages rank very well in Google and it is a way to get a good ranking for difficult keywords. When visitors come to your Squidoo page you then lead them on to your other site(s).

All in all, web 2.0 is a great opportunity for web masters and online marketers. And although his new style of marketing can take a bit of getting used to, it can also be a lot of fun.