Except the question isn't about the pure number of spam/bot accounts, it's about the ratio of spam/bots to "authentic" users. If you leave out the lurkers, that ratio gets skewed to mistakenly inflate the bot count.
A lurker isn't an active user in my opinion. Maybe that's not the same understanding as accepted definition. The lurkers might be absorbing some of the ad content, but they are not helping create new avenues for ads to be shared. Twitter's ad share surface area would increase tremendously if every user was actively producing tweets. That's the only metric that they are concerned. They don't care about how many people actually see the ads once they are there. They make their money on the potenial eyeballs alone. Lurkers are not helping increase those numbers.
I don’t follow this.. Lurkers are they eyeballs presumably.
If everyone on twitter tweeted the same amount it would probably just drown out the popular accounts and create a more diffuse and less profitable ad space I think.
The number of eyeballs allows for the price per ad to increase while the number of places ads can be placed increase the volume of ads. If lurkers are not helping to increase the volume, it doesn't make the platform as much money. Proving the lurkers are actually consuming the ads and making the ad buyer happy is non-trivial. Proving the lurkers are worth increasing the price per ad is also non-trivial. In the end, I personally feel like it is a wash by lurkers being overly represented in the fake account numbers.
As an extreme example, a single monetized tweet with a billion viewers generates money. A billion monetized tweet with one viewer obviously does not..