BtoB Magazine just released its Interactive Marketing Guide for 2008. (PDF here) The 36 page guide features a lot of great data about the state of online advertising, including the following gems:

- In 2007, U.S. marketers’ best performing advertising tactic was search engine optimization (SEO) at 57%, followed by behavioral targeting (44%) and email house list (42%). Rich media ads, which rated at 28% last year, trailed the list at 7% in 2007.

- In 2008, U.S. ad spending will break out like this:
         - Search: 40%
         - Display ads: 21.5%
         - Classified: 17%
         - Rich media/video: 9.5%
         - Lead generation: 8.3%
         - Sponsorship: 2%
         - E-mail: 1.8%

- 82.4% of marketers plan to increase their email marketing this year, compared to 2007.

- In the U.S. spending on online social networking advertising by marketers is on the rise with the following growth:
         - 2006: $350 million
         - 2007: $920 million
         - 2008: $1.56 billion
         - 2009: $2.02 billion
          -2010: $2.4 billion
         - 2011: $2.7 billion

There’s lots of other interesting data in the report, as well, so check it out.