Online Marketing: A set of tools and methods used for promoting products and services through the internet.
Traditional Marketing: Any type of promotion, advertising or campaign that has been used by companies for years. Methods of traditional market include print, broadcast, direct mail, and telephone
Online and traditional marketing are vastly different. This doesn't go to say that one method is better than the other, but both types of marketing cater to their audience uniquely. Traditional marketing targets a mass audience through specific mediums. For example, radio broadcasts reach a large number of people every day. Unlike online marketing, traditional doesn't have as customized of a target audience. Online marketing is better able to cater to specific people. However, it is still capable of a mass approach, such as viral videos.
Enjoy this South Park Clip parodying popular YouTube videos...
When I say online marketing is more specific, it's because the internet is a powerful source through its interactivity. Since online users are interactive, marketers can base what types of products you see, by simply knowing what you have been doing on the internet. For example, I am a New York Yankees fan, so I tend to see a lot of Yankees products when I'm online. It's pretty freaky.
The main advantage to online marketing is its ability to connect with people on a personal level. You are essentially building relationships with marketers, because they find out your interests, and cater to your needs specifically, and efficiently.
On the other hand, traditional marketing is good for exposing you to new things. Since the internet can be so specific, it closes doors to other things you may not know about. Traditional marking is useful in terms of learning about products you may never think to search for.