Its the age-old question.. Are you better off doing a few things REALLY GOOD or doing many things SO-SO?
Depends on your company. Small to Mid-Sized companies should definitely focus more on a few things, find their market niche and define clearly the problems they solve, and do it better than anyone else. You are small and nimble and can keep ahead of your bigger competitors by focusing on a few things. (Big companies do not move quick) As a small-mid sized company, the more markets you try and attack, the more “un-focused” your development, sales, marketing, etc. efforts will become.
Larger companies can get away with branching out and touching a lot of different markets. They have the resources and can gamble a little more.
So, depending on the size of your company, you will probably do yourself a world of good if you focus your efforts on a few things and doing them really well.