Dry BBQ rubs are typically a blend of spices and herbs combined together to create a flavour designed to enhance the food that it is sprinkled/rubbed on. There are many, many rubs out there in the market and more and more get added almost on a weekly basis. The key to getting the best result for your cooking is firstly choosing a rub that is made from high quality ingredients. Next you need to determine what type of rub goes best with what type of food eg. some rubs go better on red meat and some are better with say fish. Many rubs will give you an indication on the label as to what foods they are best suited for. Sometimes it just comes down to personal taste too as some folks like their food hot and spicey and others like it more mild.
Rubs are often used on a range of foods from potatoes to poultry and can even be added in things like ground beef/mince meat to add that little bit of X factor taste to give your guests a bit of a wow factor that they may not have experienced before with a particular dish.
Rubs work really well on large pieces of meat like Brisket, Pork shoulders or roasts. Next time you try to BBQ a large piece of pork, rub it with some good quality mustard and liberally add(as big cuts of meat can handle a lot of rub) your favourtie meat rub for that extra flavour.
So go ahead, be brave and try adding a little(or a lot) or rub to your next BBQ and see why the Americans are so infatutaed with them.