• by April 1, 2002

Presently, there are nearly two dozen researchers, investment banking firms, analysts and ad agencies that have reported estimates of online advertising revenue for 2001. But the range is wide, from a low of $2.5 billion to a high of $19.0 billion.

eMarketer – the widely trusted research firm that aggregates and analyses e-business statistics from over 1,000 research, consultancy and government sources - has selected the Interactive Advertising Bureau's (IAB) Internet Ad Revenue Report as the benchmark source for measuring the growth of Internet ad revenue - approximately $8 billion for 2000 and between $7.0 - $7.9 billion for calendar year 2001.

Accordingly, eMarketer will hold its future projections accountable based on the online ad revenue figures reported in the IAB's Internet Ad Revenue Report, which is conducted independently by the New Media Group of PricewaterhouseCoopers.

Through a process of data collection, interviews and intensive market analysis, eMarketer compared the researchers and their respective revenue data. They found that the wide discrepancies in reporting were largely due to different definitions and methodologies used by the researchers. Many, for example, do not include significant sources of online ad revenue in their compilation of data. Additionally, when all of the revenue sources as outlined in the IAB/PwC report were factored in to the individual research estimates, most of the resultant revenue figures were strikingly similar.