DeLuca's offers what your local grocery store or convenience store never will, variety beyond the American brand names. For the health conscious, there are a variety of organic products from peanut butter, jellies, and preserves, to milk and eggs to breads. For those who favor sweets of the import variety there is always swiss chocolate like Lindt in stock. There is a larger selection of bottled waters with and without flavoring as well as real entrees at the deli and fresh fruit when you don't quite have the time for anything more complicated.
The entrees are hit or miss as to taste but usually are better than edible and can be as good as quite tasty.
DeLuca's is not inexpensive but typically worth the extra penny.