It's my experience that when people do call and complain, once the
data reaches a noticeable level, they'll make an effort to do
something. I used to have a terrible time getting signal at BWI Intl.
Airport and would call every time I had to go through there. I suspect
others did too, because in a few trips, the situation was noticeably
better.

Obviously, they're going to put resources in an area where most people
will benefit. As I've said before, the equipment the end user has
makes a big difference too. Motorola phones just generally don't
perform as well in a fringe signal area, for instance.