Companies used to pay millions of dollars to splash advertisements on the front page of MySpace, back when that social network was the hottest one on the web. One of the people in charge of selling those ads was Rita Garg, a Stanford and Harvard educated mathematician and economist.

Today Garg announced, in a Tweet, that she's left MySpace and is now working on business development at Twitter Inc. Twitter keeps scooping up the leaders from other giant tech companies, ReadWriteWeb reported first last month that Bing chief scientist Alek Ko?cz left Microsoft to join Twitter as well. That sounds like as good a use of the company's coffers filled with venture capital as any.

Prior to taking the MySpace position, Garg worked at Google's YouTube, the Wall St. Journal and at Disney doing technology integration and strategy, according to her LinkedIn profile. Garg says in 1999 she "developed [an] algorithm enabling [Disney] execs to forecast lifetime profitability of new movie release across all ancillary worldwide film markets, based on opening box office weekend."

Garg went back to school and received an MBA from Harvard in 2008 and then this technologist got a business job. She worked at MySpace for nearly three years doing business development. She joined in July, 2008 - one month after Facebook first passed the old incumbent in monthly traffic.

"Rita Garg is very driven - and very likable," says Tobias Peggs, CEO of OneRiot, who worked with Garg on integrating MySpace with his company's real time search engine. Will it be the geeky Garg that filters its way through the maze of hundreds of Twitter employees, or the big time ad salesperson ala MySpace. "Both," says Peggs, "that's why she's a great hire." Thus is the drama we all get to speculate on when one former market leader is being passed by an innovator with its foot on the gas pedal.

According to its page listing official staff members, Twitter appears to have hired at least 36 people in the last 3 weeks.