They have some excellent restuarants in the program. It's not just the El-cheapo stuff either.

Some examples:

Delmonico's and Tennessee Mountain(a frequent flyertalk hangout) in Manhattan.
The GodFather in San Diego.

I picked up about 7500 miles in Continental's program last year.

Once last year, I found out a month after I ate at one place that it was in the program.
What a nice bonus 650 miles that was.