This year the combined advertising revenues of Google and Yahoo! will rival the combined prime-time ad revenues of America's three big television networks, ABC, CBS and NBC, predicts Advertising Age. 41. ______. And this week online advertising made another leap forward. The latest innovation comes from Google, which has begun testing a new auction-based service for display advertising. It already provides a service called AdSense. It works rather like an advertising agency, automatically placing sponsored links and other ads on third-party websites. Google then splits the revenue with the owners of those websites, who can range from multinationals to individuals publishing blogs, as online journals are known. Google's new services extend AdSense in three ways. 42. ______ This provides both more flexibility and control, says Patrick Keane, Google's head of sales strategy. Companies trying to raise awareness of a brand often want a high level of control over where their ads appear. The second change involves pricing. 43. ______. Click-through marketing tends to be aimed at people who already know they want to buy something and are searching for product and price information, whereas display advertising is more often used to persuade people to buy things in the first instance. The third change is that Google will now offer animated ads--but nothing too flashy or annoying, insists Mr. Keane. Google has long been extremely conservative about the use of advertising; it still plans to use only small, text-based ads on its own search sites. 44. ______. This could fuel online ad-growth even further. Worldwide ad revenue on the internet grew by 21% in 2004, and it is expected to continue at that pace for the next few years, says ZenithOptimedia, a research firm. As Google and Yahoo! are two of the most widely visited sites, this greatly benefits them. 45. ______. Terry Semel, Yahoo!' s chief executive, believes there is a lot more growth to come as companies become more familiar with online advertising. Other innovations in online marketing are said to be in the pipeline. Local search and its associated advertising opportunities are one huge growth area. This week, Yahoo! appointed another top executive to its media group, fuelling industry speculation that the website may start to produce its own entertainment content. Television stations would then have a lot more to worry about than just losing ad revenue to the internet.

[A] Instead of Google's software analyzing third-party websites to determine from their content what relevant ads to place on them, advertisers will instead be able to select the specific sites where they want their ads to appear.

[B] Google recently announced a net profit of $ 369m in its first quarter from revenue that soared to $1.3 billion, up 93% compared with the same period a year earlier. Yahoo!'s first-quarter net profits more than doubled to $ 205m on revenue of $1.2 billion, up 55% from a year earlier.

[C] Many big firms still allocate only 2-4% of their marketing budgets to the internet, although it represents about 15% of consumers' media consumption--a share that is growing. Many young people already spend more time online than they do watching TV.

[D] It will, says the trade magazine, represent a "watershed moment" in the evolution of the internet as an advertising medium. A 30-second prime-time TV ad was once considered the most effective--and the most expensive--form of advertising. But that was before the internet got going.

[E] But many of its AdSense partners might well be tempted by the prospect of earning a share of revenue from display and animated ads too, especially as such ads are likely to be more appealing to some of the big-brand advertisers.[F] Sites such as eBay, the leading online auctioneer, and Craigslist, which hosts local sites, are soaking up large amounts of spending that might otherwise have gone on classified advertising-and for everything from used cars to job vacancies. Yahoo! is expanding heavily into entertainment, with film and video clips providing another avenue for advertisers.[G] Potential internet advertisers must bid for their ad to appear on a "cost-per-thousand" (known as CPM) basis. CPM bids will have to compete against rival bids for the same ad space from those wanting to pay on a "cost-per-click" basis, the way search terms are presently sold.