Advertising revenues are going to be greater this year than originally expected, and spending on the Internet is going to shoot up 75%, according to Universal McCann Research Director and Senior VP Robert J. Coen. Overall spending should increase 9.4%, to $235.6 billion, instead of 8.3%, to $232 billion, as he predicted in December. Advertising on the Internet will skyrocket to $3.4 billion. The Internet Advertising Bureau, however, has reported $4.6 billion in Internet advertising in 1999, a disparity due to the different methods used in compiling the information. Cautions Coen, "There's a lot of opportunity for those numbers to go astray." For instance, a company can include self-advertising, bartering or bonus advertising in those figures. But, says PricewaterhouseCoopers'Pete Petrusky, who conducted the IAB report, package deals make up only 1% of the IAB figure, bartering only 4% to 7%.