I'm thinking of it similar to how corporations want their names on rooms and/or buildings at colleges. Showing a level of support which, while not a quid pro quo, shows support in a way that isn't directly linked to a benefit.

The support could come as monetary support and maybe doing the thing that PG doesn't have the time for as mentioned here (coordinating housing):

http://news.ycombinator.com/item?id=3650877