Yahoo Search Marketing is shortening its text ads from 190 characters to a 70-character block, bringing its standards closer to Google's two lines of 35 characters each, reports ClickZ. In a letter to advertisers, Yahoo wrote that as a result of the change "advertisers can generally expect to see an increase in clicks, while maintaining their conversion rates." Advertisers have a January 18 deadline for rewriting their ads; after that date, Yahoo will automatically shorten unrevised ads.

Just this summer, Google was testing longer text ads - up to 200 characters - in an experiment to improve click-through (and possibly compete with the availability of longer-length text from Yahoo).

A Yahoo spokesperson said automatic truncation wouldn't cut off ads in mid-sentence or result in incomplete ads. Many Yahoo Search Marketing's distribution partners will continue to display longer ad versions.