Through its Fake Follower Check, the software can determine how many Twitter accounts following any user is real, and how many are actually useless spam. London's Daily Mail newspaper reported that the website was started after it was revealed that "the former Tory MP Louise Mensch had as many as 40,000 fake followers".

The number of followers can translate into financial worth by marketers and advertisers.

But marketing analyst Chris Moerdyk said: "Celebs do have huge followings but it is unusual in South Africa for them to indulge in what is known as 'sponsored tweets' for the simple reason that once they start openly promoting products they will start losing their following".

Status People, on its website, says that spam accounts tend to have few or no followers and few or no tweets, but "tend to follow a lot of other accounts".

But the website also admits that the figures are more accurate for users with no more than 100,000 followers. For someone like US pop star Lady Gaga, who had just under 29-million followers by yesterday afternoon, the figures "reflect your current follower activity rather than your whole follower base".

The website then ranks the followers according to three categories - fake, inactive and good.

Some local users even refer to spam accounts as "eggs" - because of their non-existent profile pictures - signified with an unhatched egg.

A quick search of some celebrities gave the following results:

• Trevor Noah - 465,319 followers (18% of which are fake, 41% inactive, and the rest "good"),
• Rihanna - 24.8-million followers (21% good, 40% inactive),
• Gareth Cliff - 330,317 followers (46% inactive, 19% fake),
• President Jacob Zuma - 154,128 followers (24% fake, 47% inactive, 29% good).