All around America you will find that people are selling blue pitbulls which are either pure breed or half breed because the demand for these animals is so high. Breeders can tell you that these dogs can be a handful some times however it is unlikely that you will find a dog like this that is so loyal to its owner and is also good with children. Blue pitbull dogs have received a bad reputation however it is not the fault of the dog but of the owner themselves. Through bad habits and neglect these dogs are often left to fend for themselves, not knowing how to socialize with other dog or people. Training is the key to keeping you pitbull happy and content as well as showing it plenty of good love.
Affectionate dogs as they are the blue pitbull craves the attention of people 24 hours a day. You can tell if your pitbull is a pure breed by the way it treats you as the pure breeds are bred to be friendly to their owners even though they are a dog bred for hunting. The American blue pitbull terroir has a good nature and is a pet which can be trustworthy and friendly if you treat them with respect and show that you are the master.
Behavior comes from conditioning which is up to the owner to provide and conditioning should include socializing the dog in doggy training schools as well as teaching them standard rules like, sit, stay and lie down. These dogs can be very well mannered in a social environment so please do the right thing and train your dog to get along with everyone around them, including the mail person.