From eMarketer:
richmedia_spending.gifAs the paid search boom crests, the next wave of online advertising is building. Rich media ad spending grew by nearly 37% in 2004, and growth rates of more than 25% are projected for the next three years.

The barriers to rich media growth are rapidly falling as advertisers learn which rich media formats work best for their goals, how to implement rich media-based campaigns and how to track the results of the online portion of their campaigns. As a result, the market is becoming increasingly valuable for advertisers, agencies and Web publishers alike.