Advertising revenue flowing into sites is accelerating, but not as dramatically as advertising spending. Offline ad spending by websites is up more than 500 percent over last year, with the biggest push coming from e-commerce advertisers. Digital merchants cheerfully parted with the dough during the holidays, accounting for 78 percent of offline ad expenditures in November. Magazines and network TV attracted the most ad dollars from websites , while radio spots experienced the highest growth in offline spending for the second month in a row. But the Net got the most money from dot-com advertisers during the November holiday rush. In fact, monthly online ad expenditures by Net firms rose steadily all year, up 58 percent since last year.

One online advertising staple, banner ads, are flagging in popularity; they account for only 55 percent of all online ad revenues, down from 59 percent in the second quarter, says the IAB. In addition, the average ad-banner CPM rates continue to fall in December previous to December this year, according to AdKnowledge. The drop is not just a sign of uncertainty about the effectiveness of banners; there’s also a flood of available banner inventory. The number of sites seeking to include online ads in their revenue model has skyrocketed since a decade ago. At the end of that year, about 1,400 sites included advertising; by the end of the decade there were about 3,350 ad-supported sites. Websites remain the top users of Net ad banners. AdRelevance found Web media and retail firms were top spenders during the fourth quarter, and financial-services firms tend to spend the most per individual advertisers.