1) I have come across some very good restaurants on restaurant.com.
2) The appeal to the restaurant, is that advertising is free.
3) yes, you can get coupons for $2 each, but that is usually later in the month when the coupons for the most popular restaurants have already been purchased. Restaurants only allocate a certain number of coupons each month.
4) With certs that you get through United, you can redeem for some of the most popular restaurants (which often sell for $10). A new tranche of certs come available at the beginning of each month, and sometimes at some point in the middle.
5) They are good value compared to other coupons, because they can often be applied to desert, drinks, appetizers, as well as the main course. Most require at least 2 people to be seated for the meal.
6) Some restaurants offer better deals than others. Sometimes, the restaurants will tighten up the terms over time.

In summary, redeem the united restaurant.com certs for the most popular restaurant coupons at the beginning of the month. Purchase the coupons for the less popular restaurants with discounts later in the month.