At blur, we love a good slogan. But recently, we’ve been wondering if a great slogan can be a liability for a brand, because it’s just so easy to spoof something familiar. Here’s what we mean:

A Diamond is Forever. De Beers’ famous line celebrated its fiftieth birthday in 2007 and shows no signs of slowing up. It’s a regular feature on ‘best slogans’ lists, and was even the title of a James Bond novel and film. The phrase evokes a kind of untouchable glamour. But Kanye West used this association to creat dramatic contrast with his song ‘Diamonds from Sierra Leone’ which sampled Shirley Bassey’s Diamonds are Forever. West used the appeal of the slogan as a platform to criticise the trade in diamonds that fund civil wars, from suppliers that enslave children. The music video featured child mine labourers in Africa in contrast with Western people buying diamonds which spurt blood. The video ends with “Please purchase conflict-free diamonds,” and helped bring the problem of blood diamonds to the public’s attention. These days, though, many young people associate the phrase with Kanye West rather than De Beers.

We love Have a Break, Have a Kit Kat. It’s concise, funny and it’s got legs. Millions of workers identified with ads like this, showing a dull office existence relieved by the arrival of a Kit Kat. The meme was so successful that Greenpeace successfully hijacked it to make a point about Nestlé’s destruction of the rainforest. They produced this video featuring an office worker taking a break from shredding paper with a Kit Kat. But the wrapping was peeled away to reveal the severed hand of an orang-utan upon which he contentedly munched, ignoring the blood seeping down his face. Greenpeace also produced the fake logo shown in the picture. By working within the established brand meme, Greenpeace communicated its environmental message far more effectively than it could have done with placards. Unfortunately, we can’t quite look at a Kit Kat the same way again.

The two-way nature of digital communication renders highly recognizable brand names susceptible to brandjackings like these. And the humour of seeing a familiar meme subverted makes the resulting campaign or song more likely to go viral. Some savvy brands realise this can actually be used to their advantage. May we present you with The Man your Man could smell like campaign, from American ‘man freshening’ company Old Spice, featuring the world’s most alpha male. If you only watch one YouTube video today, make it this one. The tongue-in-cheek advertisements invite parody, and the digital community has been glad to oblige. Here are the most popular parodies, and here’s our favourite, which has racked up over two million views. With such a silly campaign, viral status came naturally – without detracting from the central brand message.

These three brandjackings are very different, showcasing the particular strengths and vulnerabilities of a cracking brand slogan. And if you want your own unforgettable line, for better or for worse, brief the Exchange.