Twitter is embracing Jack Dorsey as its chief executive in the hopes that its once-spurned co-founder can hatch a plan to expand the short messaging service’s audience and end nearly a decade of financial losses.

Twitter’s departing chief Dick Costolo says that while he is confident in the current direction of the company, he also is willing to let the next CEO make the changes the person wants to make.

In May 1954, English runner Roger Bannister broke the seemingly impenetrable barrier of the sub-four-minute mile, a month after his rival John Landy proclaimed it to be impossible.

Twitter has hired Nathan Hubbard, the ex president of Ticketmaster, as its first head of commerce, part of a push to enable shopping via short postings on its social website.

MYSPACE is expanding its programme for letting advertisers target their pitches using personal details on users’ profile pages.