'Up to' 23 million active Twitter users are bots which tweet automatically

"Twitter has admitted that as much as 8.5 per cent of its userbase - some 23 million accounts - are bots which automatically ping the site with updates, but the company has also revealed that more human users are seeing ads served on the site than originally thought.
As many as 23 million of Twitter’s 271 million monthly active users are bots, the site has revealed.
In its 10-Q document filed with the US Securities Exchange Commission yesterday (11 August), Twitter revealed a new metric comprised of users that have used third party applications that automatically contact its servers without “any discernible additional user-initiated action”.
Those 23 million accounts could include useful news services, earthquake updates or retailers that automatically update followers of new items in stock, alongside spam accounts. However, Twitter estimates false or spam accounts represent fewer than 5 per cent of its monthly active users.
The new metric is a point of interest to marketers, as it means a large amount of the 271 million active monthly users Twitter reported last month are not real consumers that have the potential to view and interact with their advertising and organic content.
However, Twitter also used its filing to revise upwards the amount of users that can see its ads. In its second quarter earnings Twitter said as many as 14 per cent of its users were using third-party applications to access its service, meaning up to 38 million users were not being served with ads.
Twitter has updated that number to 11 per cent, saying it has now found after “reviewing and refining its processes” that some of those users had in fact accessed its service through owned and operated applications such as Tweetdeck. This means 89 per cent of its total active user base can see ads served on the platform."
Source:  Marketing Week, 12th August 2014