15M is nearly 5% of Twitter's active users, or all the growth they've had in 2015. Assuming these bots are "active".

If it's true, I wonder what effect it will have on the value of Twitter(I do assume this isn't the only one).

If it turns out half the use base is made out of bots or non-active registered users that is.

Besides these 'obvious' bots, there are more that have humans in control, but which the humans never read tweets, they just post them. I would bet, though have no data, that there is a large percentage of these 'post-only' accounts. Not sure if they should be called bots or not...

$1M from 15M fake accounts is rather low.

6.67 cents per account.

Isn't it easier and much more profitable to fake click ads at such scales?

Also getting 15M fake accounts means getting 15M fake emails, which isn't cheap:

https://buyaccs.com/en/

>Also getting 15M fake accounts means getting 15M fake emails, which isn't cheap

Unless you create them yourself, which seems rather logical if you're in the account creation business anyway.

You don't need to verify email to use Twitter.

So you spent $40,000 to reveal those bots? All to write a short blog post?

Am I missing something?

I think that's how much it would cost or the full amount. I do think they spent $400 though. Very weirdly written article.