Ever wondered why one store that is very like another
will move into a space just across from or next to its
competition?  It is because both stores then make more money.
When museums are scattered around the same park, people often
go from one museum to another, not to just one.  I have twice
been in cities where the local museums had gotten together on
a common subject, and it was great!  In Memphis one summer, the
civic center had "Ramses the Great," the Pink Palance had an
exhibit of how mummies are made, another had contemporary photos
of Egypt, and so on.  In Louisville, Kentucky another summer,
all the museums seemed to be doing quilts - quilts as history,
quilts as art, quilts as a family activity.  There was one
guidebook for maybe 4 or 5 different exhibits.  People who had
seen and enjoyed one show seemed much more likely to want to
buy the catalogue and go on to the other shows.  I was with
friends who are only moderately museum-loving, but who became
more so from doing all the quilt shows.  It could have been
competition, but it turned out collaboration and was good for all.