eMarketer reports that according to a recent survey from WebTrends and iProspect, 41% of U.S. marketers are currently running paid search engine marketing (SEM) efforts.

The survey also found that 41% of those marketers who are implementing SEM strategies are measuring these efforts using click-through metrics and general site traffic. Only 11% are using a detailed ROI analysis of their SEM efforts, reports eMarketer, which includes lifetime value as well as revenue by phrase.

Other findings:

• 23% of those running SEM campaigns said they’re a significant part of their overall marketing mix
  
• 23% of marketers aren’t using SEM at all, but 35% are evaluating the option.

The data was collected in a survey of more than 800 marketers by WebTrends and iProspect at a Web conference presented by the two firms.