Ask any ex-Yahoo employee what's wrong with the company and one of the first three things they'll tell you is that the place is too slow.

Too slow to figure out what to do. Too slow to do it.

After two months on the job, Yahoo CEO Marissa Mayer is aware of the problem.

On Tuesday, she gathered all Yahoo employees for an all-hands meeting to announce her turnaround plan for the company.

According to sources familiar with the details of the meeting, one of her major changes to Yahoo is how the company will decide which products to ship.

Mayer's rule: If a new product can't be shipped in six months, and if it doesn't have a realistic shot of reaching 100 million users or generate $100 million toward the company's top line, then Yahoo will no longer bother.

This is a major change in metabolism for Yahoo. It's the flipside of all the new perks Yahoos are getting: accountability. Mayer expects employees to work harder and longer. That's why the free food is there and the lights are on later.

If you really want to get a Yahoo employee, shareholder, or former employee fired up, ask them about how long it took for Yahoo to launch Panama, a search ad-selling platform that was announced in 2006 in response to Google's insane growth.

Back in February 2011, Yahoo announced that it would launch a news-aggregator app for tablets called Livestand by June 2011. Presumably, Yahoo would not have announced the product if it had not already been well under development, perhaps for a few months. Yahoo did not end up shipping the product, called Livestand, until September 2011 – almost a year after work first started on it.

Mayer picked up this pace from Google, where she made her fame and fortune as a product manager/marketer. In the first few years after Google had already established itself as the dominant search company, it became infamous for a throw-the-noodles-against-the-wall-and-see-what-sticks product development strategy. Yes, the results were mixed; it came up with winners Google Maps and Gmail, but also duds like Google Video, Froogle, and Google Answers. But mixed results are better than no results, which is what Yahoo product development has been up to lately.