Curt Viebranz, fired as president of AOL's sales arm after just half a year, may have lost a struggle with the internet portal's bosses. But he's unlikely to be the last executive casualty at the Time Warner unit, New York's biggest internet business. Alley Insider reports Viebranz may have been fired because he refused to sign up to unrealistic ad sales targets. But why were the bosses' expectations so unreasonable?

One possible explanation: Viebranz's immediate superior, AOL chief operating officer Ron Grant, is vulnerable under the new Time Warner regime of Jeff Bewkes, who took over as chief exec of the media conglomerate at the start of the year; Grant's intelligence may have won him a moniker, the "human computer", but Bewkes is thought not to rate his management ability. The bloody dismissal of Viebranz is not necessarily a sign of Grant's strength; but his weakness.