NEW YORK: The advertising landscape stateside continues to shift as the web grabs increasing numbers of US marketing dollars. But like television, where four networks dominate, online also has its coterie of giants.

Google, Yahoo, MSN and AOL between them take the lion's share of web adspend. Latest figures from the Interactive Advertising Bureau show the top ten online companies accounting for 72% of all web ad revenue last year, up from 71% in 2004, while the top five account for more than half of all spending.

The much vaunted democratization of the medium is little in evidence while marketers' mindsets still appear to be in thrall to the concept of 'tonnage' or reach.

The reach of the big players makes them easy places for marketers to spend their ad budgets. In addition, the manpower involved in planning, buying and tracking ads across many smaller sites, makes the one-stop approach seem more efficient.

Smaller sites have to attract advertisers' attention with heavily customized deals, tailoring large-scale, one-off packages for marketers who are comfortable with the online medium but who would normally place their faith in Google or Yahoo.

Comments Simon Assaad, co-founder of "Our job is . . . giving them a reason to move money from Yahoo to Heavy. We say here's a custom opportunity for you to own something just for our audience. You can't do it with banners or buttons or title sponsorships."

The Online Publishers Association is trying to persuade agencies of the efficacy and better targeting offered by smaller sites.

Says OPA president Pam Horam: "Branded rich-content developers provide a more efficient environment."

Internet ratings service. Quantcast measures site demographics more deeply by using technology that tracks what visitors frequent online.

Declares co-founder Konrad Feldman: "The idea is if you can reaggregate enough of those niches, then you get an audience that's much more highly targeted. The challenge is understanding the audience of a site that's too small to be covered in traditional research."

Data sourced from; additional content by WARC staff