User-generated ads: Just as everyday readers can now effortlessly contribute articles and images to newspapers, advertisers have begun to invite Internet users to create their own ads for company products, mashing together material provided by the company with their own input.

This is not a direct hit to newspapers. Such promotions will still have to be advertised somewhere in order to pick up steam. But if and once they do, chances are the original ads won't stay up for long due to the viral nature of the Internet.

Most static advertising on newspaper websites bores or is not noticed by users and therefore, those users don't spread the word. But if a company gives readers something fun to do through which they can be creative and express their own ideas about a something, they're likely to tell their friends who will tell their friends, etc.

And those friends won't be saying, "Wow! Look at this ad I found on my favorite newspaper website." They'll simply just send the link of the promotion, skipping the paper altogether. 

Classifieds and Real Estate: On the other hand, Craigslist and now Google Base hit newspapers with a double whammy. Not only have they destroyed the lucrative classified ad business model, but they are also cutting into the revenues of real estate agents meaning they'll spend less in the newspapers in which they tend to advertise.  

Google Base, which to some looked like Craigslist on steroids, was bad enough. But four months after its launch, those steroids have kicked in to produce Google Real Estate, essentially an easily searchable compilation of all the housing classified information contributed to Google Base by its individual users. As younger generations grow up with these technologies, there is little to no chance that they will ever consult nor advertise in a newspaper for classifieds and real estate.

News.com also speculates that Google could be starting a dating site with Google Base's database. Between that and sites like MySpace, the currently booming online dating market could soon take a major hit meaning newspapers could soon be losing those ad dollars as well.

What's more, the Wall Street Journal reports that there is a boom in demand for tracking the effectiveness of advertising. What happens if it turns out that the most effective type has nothing to do with newspapers? 

Sources: The New York Times (through PJNet), Wall Street Journal (real estate), News.com (user-generated ads, Google Real Estate, personals)