Why are out of town shopping centers being built in the suburbs?

because shopping centers don't like any competiton so that's why they are usually built far away from main districts!

The concept was to build "all in one place" shopping environment's. Developers could create a large retail park where they provided substantial parking, bring in large name retailers and provide each outlet with captive customer traffic (all in one place undercover). This was greatly different to the high street stores which were restricted to their size by the buildings available. Customers found that the high street was fine on warm inviting days but on the wind swept, raining or snow days it was uncomfortable and customers shopped in a hit and run process whilst dodging the rain - The carrying limit went down as more goods were purchased and had to carried by the customer to their car. In the large shopping centre multi purpose shopping trolleys moved around the building reducing carrying limits and keeping the customer dry and content. Browsing was encouraged and the customer added to the necessities they originally stepped out to buy.