US online marketing is expended to double by 2010.  During that same period, online spending is expected to triple, rising from $16.9 billion to $42 billion.  

69 of the top 100 advertisers reduced their spending on traditional media from 2005 to 2006, while 70 of the same top 100 advertisers increased their spending on online ad campaigns during the same period. 

2007 ad spending online will be higher than radio.  Advertisers will be spending $100 per person to reach people online in 2007 and that number is expected to increase to $200 per person by 2011.