A quote from the site I linked to explains why it is so good.

A spinach artichoke dip can be an excellent appetizer for festive dinners. It is healthy and tasty and it can be combined with many other ingredients for creating a unique recipe each time you cook it. Both spinach and artichokes are healthy foods, rich in essential nutrients and easy to find all year round. Besides, they aren’t included on the list of high allergenic foods, very few cases of allergy to spinach or artichoke being known. Spinach is an incredibly rich source of vitamins and minerals. For instance, a cup of spinach leaves contains about ten times more vitamin K than the daily recommended intake value and about 4 times the vitamin A recommended daily dose. It is also rich in folate, iron and magnesium. In the same time, spinach is a low-calorie food, one cup containing about 40 calories. Other nutrients contained in spinach are lutein, very good for eyesight, vitamin E, good for mental performance, vitamin C, good for strengthening the immune system, and omega-3 fatty acids, useful in slowing down the aging process. Artichoke is also considered a healthy food, thanks to its anti-oxidant properties which help support the liver functions and which are thought to play an active role in decreasing the LDL cholesterol levels. Like spinach, artichoke is low on calories. This is why foods based on spinach and artichokes can be included in weight loss or maintenance diets. This depends, of course, on the other ingredients that are added to the mix.