• by Joe Mandese  @mp_joemandese, June 17, 2008

A week after one industry ad tracker estimated online display advertising climbed 8.5% during the first quarter of 2008, another estimates it actually grew at nearly twice that rate.

"Internet advertising impressions grew by 14.7% in the first quarter of 2008 over the same period in 2007," Nielsen Monitor-Plus said Monday, as part of a broader quarterly tracking report for the major media it measures. On June 11, TNS Media Intelligence estimated that online display advertising rose only 8.5%.

Nielsen also implied that the TNS MI data reflects the most tepid part of online advertising growth, noting: "Sponsored search link advertising drove overall growth, and rich media led growth in the display category."

While Nielsen did not break out those online advertising platforms, it did disclose which types of advertisers are driving demand for online search.

"The health and telecommunications industries posted strong increases in sponsored search link impressions--up 108% and 80% respectively," Nielsen reported, adding: "Hardware and electronics advertisers drove results in display impressions with 65% growth, followed by automotive and consumer goods companies, who posted increases of 45% and 42% respectively."

That's the good news. In a potentially alarming finding, Nielsen said financial services marketers--historically among the largest online advertising categories--decreased their spending during the first quarter in both sponsored search impressions, which were down 15%, and display impressions, down 13%.

The growth of all online advertising components during the first quarter is especially impressive, since Nielsen estimates that overall measured media ad spending climbed only 0.5% during the quarter.