Compete, the Boston- based online traffic analytics firm, has been bought by UK-based market research and intelligence firm Taylor Nelson Sofres, for a total that could go up to $150 million. The price includes $75 million in upfront cash and about $75 million earnout in the next two years based on performance.

Compete’s revenues for 2007 were $14.9 million, over 50 percent higher than 2006, and gross assets in 2007 were $11.2 million. The company made a loss of $4.5 million in 2007, as it invested in building its panel and industry expertise, the company said. It had raised a total of $43 million in three rounds of venture capital, and investors included Charles River Ventures, Idealab, Split Rock Partners and William Blair Capital Partners. The site was started in 2000 by serial entrepreneur Bill Gross, who had previously helped create the search engine that became Overture. More details in release here.

From Compete’s company blog: “[This acquisition] means joining our clickstream data with TNS’ massive consumer panel operations, consumer research capabilities and ad measurement databases on a global scale.”

This continues the consolidation in the online measurement space, as companies like Hitwise and others are now part of bigger companies. The only two major independents with any size in the market are now Comscore (NSDQ: SCOR) (a public company) and Quantcast (which recently raised $20 million in funding)...both of them have been M&A targets for a while.

Update: In a post on TechConfidential blog on the valuation on this deal, some good points about whether Compete got a good price: “Compete is small and unprofitable...By comparison, in 2007 Experian Group Ltd. paid $240 million to acquire another leading Web intelligence company, Hitwise Pty Ltd., which made money and had annual revenues of roughly $40 million. In other words, at a price tag of $75 million TNS is offering roughly 5 times Compete’s trailing revenue, and it will pay 10 times sales if the target reaches the financial milestones stipulated under the earnout. Experian paid a multiple of only 6 times sales for Hitwise.”

• Analytics Company Compete.com Raises $10 Million In Third Round