Seller response time for messages....sucks for some.

I know some sellers are better than others for when a question is presented. The top five are usually on it, TMF, PV, 7EE, RepsMaster and Kickzlucas. But, some like i stated suck. Im sending messages, it's taking some 3 to 5 days before a response if they respond at all. ( SHOE TIM, and FACTORY DIRECT ) If they cant give a simple we are busy or we will get back to you, this makes one want to seek elsewere to make a purchase. Anyone else experinceing long delays on questions or any discussions at all?