Jupiter Research reports that only two online ad categories - automotive and travel - are both top spending categories and are predicted to be among the top growth categories in the next five years. Predicting that the online ad market will grow to $16.1 billion by the end of 2009, the analysis predicts that automotive, health, travel and household goods will grow at various rates between 15 and 34 percent. Current market leaders are expected to stay on top, with media and entertainment taking the top position ($2 billion in yearly spending by 2010), financial services ($1.7 billion), automotive ($1.4 billion) and travel ($1 billion).