The software, called WebTrends Dynamic Search and delivered as an on-demand service, expands WebTrends’ Lab product family aimed at online marketers.

The software is underpinned by WebTrends’ core True Optimization technology that automatically determines which combinations of keywords, positions, web pages and networks perform best. The results help online marketers drive allocation of advertising spend across search engine networks like Google, Yahoo and MSN.

Officials at the Portland, Oregon-based company said the new software addresses a pressing need in the so called paid-for search also called bid management – market.

Paid-for search is best described as a search engine marketing model in which websites pay a search engine company to guarantee their sites will pop up in various keyword searches. It guarantees that a web site will be indexed and ensures that a search engine’s crawler software visits the site more frequently.

The growth of search engine marketing has brought rising keyword costs, and increasing complexity has made it more difficult for advertisers to profitably scale their efforts, said WebTrends CEO Greg Drew.

Drew added that traditional bid management tools used to manage bids on pay-per-click search engines often come with a hard manual graft, requiring marketers to manually monitor, measure and tune dozens of variables for hundreds of keywords.

WebTrends isn’t the only vendor to provide paid-search optimization tools. Rival WebSideStory Inc also includes keyword bid management tools as part of its new Active Marketing Suite.