Haven't heard of Vanessa Colella? You likely will, in the months to come, as Yahoo president Sue Decker tries to solidify her control over the troubled Internet giant. Colella, a brainy MIT Ph.D., joined the company as a VP earlier this year, and was rapidly promoted to SVP of "insights," reporting directly to Decker. We'd heard about a shakeup in Yahoo marketing, but it involved Colella's promotion, not a change in role for Allen Olivo, the old Valley brand hand, as we first suspected. Olivo had best watch his back, though."Insights" is a Valley term for analytical marketing — taking the vast amounts of data generated by users' Web activity, and acting on that information. This used to be the realm of Usama Fayyad, Yahoo's now-departed chief data officer. With the departure of traditional brand marketer Cammie Dunaway, and the ascension of Colella, I'm begining to see a pattern. Decker is trying to replace art with science — marketing by the numbers. It's a shift Decker has already made in Yahoo's sales department, starting with the disgraceful forced departure of respected ad-sales chief Wenda Harris MIllard, a botched exit which is still talked about on Madison Avenue. Millard, now at Martha Stewart Living Omnimedia, has loudly defended the role of art in the sales process, the notion that human intelligence can sometimes better match advertiser and audience than an automated exchange. Decker and Colella may have an easier time automating Yahoo's marketing efforts, though. Pop quiz: What does Yahoo's brand mean? Right. When you're starting with a blank slate, painting by numbers may be the easiest solution.