When Carol Bartz took over Yahoo, she wanted to make the company more focused, and increase operating margins.

In order to hit both of those targets, she's taken a machete to the company, lopping off irrelevant, or underperforming divisions.

In some cases, the cuts make sense -- Geocities, anyone? In other cases, her cuts are hurting some people's feelings (but still make some sense) -- Delicious, anyone?

Regardless, if you step back and look at it, Bartz has sold, shut down, or plans to shut down over $4.8 billion worth of mergers and acquisition work from Yahoo's lifetime.

The bulk of that comes from the $3.6 billion it paid for Geocities, though. Cross that out, and Yahoo has killed $1.2 billion worth of M&A.

Sounds bad, but it's not like that $1.2 billion is for naught. It got some of the money back by selling these properties. Also, Yahoo probably got some value out of the acquisitions along the way.

Still, it's crazy to stop and think about how much value has been incinerated, especially since Google and a number of other companies are on a M&A jag.