I need someone to tell me what the following would be called: Let's say I sell a USED PRODUCT on eBay. I grow the category SO LARGE that it makes BILLIONS per year on eBay alone. Let's say the impact was so heavy that it started making serious dents in the profits of brick-and-mortar RETAIL stores, that carry the same item, NEW. The manufacturers/distributors/retailers were damaged by that, and had to adjust their prices accordingly; or maybe even go out of business because the RESALE angle caused the RETAIL to implode in on itself. It's like a 2ndary market causes a massive draw from the primary market, and causes a sort of "vacuum" ?, could I call it ? What is that economic term called ? Thank you.