Most read stories in advertising, marketing, media and PR (18 - 24 Nov 2012)

Early last week, history repeated itself for Churchill Insurance when it had to end its relationship with the star of its TV ads, this time Martin Clunes, after he was banned from driving. In 2005 Churchill dropped Viz Reeves after being charged with drunk driving. (Marketing, 19 November)

After increasing pressure to prove the ROI of its advertising Facebook started testing a tool that it claims will help marketers track the return on investment from advertising campaigns on the social networking platform. (Media Week, 19 November)

Microsoft revealed it is going to feature The Hobbit characters Gandalf and Bilbo in advertising for its Windows Phone 8 operating system. (Marketing, 20 November)

In a week when Sally Bercow was forced to leave Twitter after getting into more legal bother British Airways had to quickly apologise after re-tweeting an offensive message. (Marketing, 20 November)

As a couple of the grocers fight accusations of sexism for their Christmas ads, Asos, the online fashion retailer, decided to go the other way and attack Christmas clichés in an online film for its range for men aged 18 to 25. (Campaign, 19 November)

Reckitt Benckiser is backing its Cillit Bang cleaning brand with a £5m push, bringing back brand ambassador Barry Scott to its TV ads after a four-year hiatus. (Marketing, 19 November)

Speaking not long after the Office of Fair Trading begun its investigation into how retailers use online data to target shoppers with personalised prices, Sainsbury's marketing director Sarah Warby said the supermarket was not "afraid" to use its data for marketing as it identifies changing shopping habits. (Marketing 22 November)

There were a few sore heads in medialand on Thursday morning and none more so in Holborn (you would imagine) after MediaCom got the Grand Prix for winning the most awards at the Campaign Media Awards on Wednesday night. (Campaign, 22 November)

In Campaign’s viral chart Red Bull claimed another victory with a five-minute video that was shared more than half a million times, while the John Lewis's Christmas ad was pushed into third place by a video of Barak Obama. (Campaign, 16 November)

Readers who missed ITV’s new logos and branding when they were unveiled read the thinking behind the changes this week (Marketing, 16 November), while the personnel changes at McCann Erickson had nothing to do with its departure from the HSBC global pitch list. (Campaign, 20 November)

Over in the PR world there was trouble at the Chartered Institute of Public Relations, which will have to rerun its presidential election after complaints over how it was handled. (PR Week, 19 November)

In new business news BT is on the hunt for a new PR agency ahead of the launch of its sports channels next year (PR Week, 21 November) and GolinHarris picked up Cadbury's entire UK consumer PR work, ending Cadbury's relationship with The Red Consultancy and PrettyGreen.

There is no end of warnings for users of social media this week and Bell Pottinger chairman Lord Bell said his client Lord McAlpine’s legal pursuit of Twitter users who wrongly implicated him in child abuse could be a "watershed moment in slowing the growth of smearing". (PR Week, 21 November)

Most shared things on Twitter

The growth of social networks [infographic] - The Wall

Social Media Strategy: Many people retweet links without reading them [infographic] - The Wall

Twitter to give $1 million dollars to small businesses for #SmallBizSat - The Wall

Why it pays to integrate mobile to marketing campaigns – 5 Things mobile campaigns need - The Wall

Black Friday adverts prompt social media buzz, but are TV adverts really driving the conversation? - The Wall