The UK recently evaluated the online ad market and found that Google and Facebook commanded 70% of all online ad spend in the country [0]. Their large pool of advertisers also helps them command a higher return per search compared to other platforms, allowing them to outbid its peers to become the default search choice on devices, e.g. Apple products. Their lack of privacy sensitive policy also helps their ad targeti…
Every company is a monopoly based on how you define the market. Why should we focus only on online ads ? Why not look at the entire ad spend and then see what % is controlled by Google ? By some logic the coffee shop in my block has a monopoly on coffee if their market is the block. They are irrelevant if you look at the entire city.
But to successfully implement anti-competitive practices, you do usually need a significant portion of market share. Which is pretty much what’s being discussed here, even though it’s not a very accurate use of the word. You can also do it by acting as a cartel, which is another situation commonly (though not very accurately) described as a monopoly.