Twitter has sailed passed the 10 billion tweet mark, but who posted the 10 billionth tweet is still unknown.

This is something of a landmark for the micro-blogging site and one which shows just how popular Twitter has become – especially if you consider that the 1 billionth tweet was only sent in November 2008.

The site with the keys to the Twitter counter is Gigatweet, which keeps tracks of all the tweets sent to Twitter in real-time. Don't stare at the counter for too long, though, as it can get a bit mesmerising.

Businesses to busy to tweet?

We would love to reveal what the 10 billionth tweet said but the person's account has been protected.

We're hoping it was something witty, irreverent and nuanced. But we're expecting it's about what that person had for dinner.

As if by magic, Virgin Media Business has done some research to coincide with the landmark tweet, noting that – when it comes to businesses – despite 57 of the FTSE 100 signing up to Twitter, the study found that almost three-quarters (72 per cent) have not used their account to respond to customer enquiries or comments made about the company.

This is something that's surely going to rile those who use Twitter to get actual responses from companies without having to go through the rigmarole of call centres and the like.

We're expecting Twitter to hit landmark numbers again this year. Doing some rudimentary maths it seems that if the 1 billionth tweet was in November 2008, the 5 billionth in Ocotober 2009 and the 10 billionth tweet was in March, then this points to the 20 billionth to happen in around the four month mark.

We'll keep you posted in July.

Via Mashable