• Ad spending on social network sites in Mediapost (registration required): “Ad spending on social network sites is set to top $1.8 billion by 2010, but the network operators such as MySpace and Facebook must develop tools to measure results.”

What it means: according to this eMarketer report, 2007 ad spending will be at $865M on these types of sites with MySpace getting 60% of those revenues. Looking at 2010 numbers, I believe social networks might become an advertising category of its own.

• SideStep buys TravelPost via Search Engine Watch: “TravelPost, with over 500,000 hotel reviews on its site, might be the smartest little travel site you’ve never heard of. The coolest feature is the ability to filter hotel reviews by Age, Gender, Budget, and Trip Purpose. TravelPost requires the reviewer to enter demographic information before posting.”

What it means: many larger organizations are buying small established companies instead of building from scratch. Also, I like the idea of having demographic information on user-generated content. Finally, I think word-of-mouth certainly plays an important role in any travel decision and therefore benefits from user-generated reviews and descriptions.