Summary Box: Demand Media stock up on renewed hope

THE SPARK: Demand Media Inc.’s fourth-quarter earnings and outlook for this year gave investors hope that it is starting to recover from diminished traffic that had stemmed from changes to Google’s Internet search formula.

THE RESULT: Its stock soared by more than 30 percent Friday.

THE TROUBLES: Investors had braced for the possibility of a weak performance, given Demand Media’s struggles since Google dramatically changed the way it ranks websites last February. Demand Media is trying to adjust by putting more emphasis on longer, more in-depth articles that are more likely to rank high on Google’s search results.