Spending on online display ads in the first three months of the year surged 46.4 percent from the first quarter of 2005, according to data released Monday by Nielsen Monitor-Plus. But the portion of
ad budgets devoted to the Internet remained small--5.25 percent as of April, compared to 3.51 percent in April of 2005, according to Nielsen//NetRatings, which excludes paid search, sponsorships,
promotions, desktop advertising and some other types of online ads from its calculations. Overall, ad spending in all media through the first quarter rose 5.6 percent from the same period last year.