Red Sox deal Casey Kotchman for Bill Hall

It's been spread on Twitter that Casey Kotchman is headed to the Mariners for Bill Hall, a minor league PTBNL and cash considerations. When I first saw this deal I was curious to what this accomplished, but after looking at the numbers this makes a bit more sense. The cash is likely the money that Seattle got from the Brewers when they got Hall to cover some of his 2010 contract. So they are probably not adding contract and could be dropping some.