Why are there duplicate listings on KW.com and/or my market center's site?

Our KW agent/market center sites, along with KW.com and the KW consumer app, currently display all listing data we receive from the MLSs in the area. If a listing is input into multiple MLSs, and we have an IDX agreement with each of those MLSs, then all entries will be displayed on KW.com, KW agent/market center sites, and the KW consumer app. 

For example, an agent inputs their listing into 3 different MLSs that their Market Center typically uses. Because the market center uses all three MLSs consistently, they've set up IDX agreements with all three of those MLSs and KW. As a result, searching for this particular listing on KW.com will display 3 different search results of the same listing for the consumer.