They can’t both be a monopoly in the same business. That would be a duopoly or a cartel. However between the two of them they collectively control about 51% of

They can’t both be a monopoly in the same business. That would be a duopoly or a cartel. However between the two of them they collectively control about 51% of the online advertising market. They’re the heavy hitters for sure, and do dominate some market segments, but is two companies each having about 25% of a market a monopoly? Google’s market share has been declining for 5 years. Amazon’s share is rising fast. Is a triopoly a thing? Even if it was, we don’t have one anyway. Sure there is cartel like behaviour going on. That needs to stamped on hard. I’m not against action where it’s needed, I just see a lot of vague uninformed and inaccurate comment on this issue. Uninformed outrage is a dangerous combination.