> If tying (assuming there's a consistent definition the word) is such a bad idea to begin with why does it matter whether it's done by a company at 90% or 10%

> If tying (assuming there's a consistent definition the word) is such a bad idea to begin with why does it matter whether it's done by a company at 90% or 10% of market? Equality under the law should be the measure. There is nothing inherently wrong with tying, which you might also call "bundling." Quoting from the FTC's website: Offering products together as part of a package can benefit consumers who like the convenience of buying several items at the same time. Offering products together can also reduce the manufacturer's costs for packaging, shipping, and promoting the products. Of course, some consumers might prefer to buy products separately, and when they are offered only as part of a package, it can be more difficult for consumers to buy only what they want. For competitive purposes, a monopolist may use forced buying, or "tie-in" sales, to gain sales in other markets where it is not dominant and to make it more difficult for rivals in those markets to obtain sales. This may limit consumer choice for buyers wanting to purchase one ("tying") product by forcing them to also buy a second ("tied") product as well. Typically, the "tied" product may be a less desirable one that the buyer might not purchase unless required to do so, or may prefer to get from a different seller. If the seller offering the tied products has sufficient market power in the "tying" product, these arrangements can violate the antitrust laws. https://www.ftc.gov/tips-advice/competition-guidance/guide-antitrust-laws/single-firm-conduct/tying-sale-two-products https://www.ftc.gov/tips-advice/competition-guidance/guide-a...