Beware the all-seeing eye of the internet – it can react, and punish, in an instant.

Such was the experience of Tesco, which earlier this month found itself on the receiving end of a dry, witty, and at times surreal Tumblr blog dedicated to its Express store in Haggerston, east London – or the “worst place on Earth”, as the author had it.

The blog published photos of the chaos and debris that seemingly littered this branch of Tesco, with produce stacked haphazardly on the floor and trolleys abandoned in the aisles, while complaining of the constant lack of staff. “I just want some cleaning products. Why is that too much to ask?!” ran one caption, beneath a picture of empty shelves.

An instant hit, the Tumblr was soon attracting comments from fellow Haggerstonians keen to share their horror stories: “I’M SO GLAD SOMEONE SET THIS UP. Every time I have to go in there I get worked up into an infernal rage.”

Within 24 hours, the Worst Tesco blog was generating media attention, and Tesco did the only thing it could: it contacted the blog author on Twitter and took steps to remedy the situation as quickly as possible.

The store is now under new management and the old chaos is no more. In the space of 13 days, the blog has achieved what it set out to do (though I doubt the author ever expected it to have such an impact).

Reflecting on the Haggerston saga, Tesco chairman Sir Richard Broadbent told The Sunday Times this weekend: “The world is becoming more volatile, things spread much more quickly, the groups that people trust have changed. We don’t defend problems, we tackle them. Any organisation has to be much more open, transparent, and responsive.”

The Haggerston episode is encouraging because it displays the people power of the internet at its best; and it shows that even the biggest retailers can listen, react and make amends (though quite how Tesco Express Haggerston ever got into that state is another matter).

It’s a reminder, too, of how humour can pull levers that more straight-laced campaigns cannot. The Haggerston Tumblr caught the imagination – and achieved its goal – because it was funny. Likewise, the @WHS_Carpet Twitter feed, “documenting the wonders of the abject carpets at WH Smith”, celebrates the epitome of high-street mundanity.

Tesco handled Haggerston correctly – and its reward may just be the ‘My Tesco Metro Is Superb’ Tumblr, set up in response to the Haggerston blog, which celebrates a branch in a former pub in west London, because, as the author says: “I’m concerned some Tesco’s aren’t as truly wonderful as mine.”