You might like their products, but would you get the Apple logo tattooed on your foot?
Mr Johnston is in the process of having his arms covered in what tattooists describe as "sleeves", but the Apple on his wrist will remain the only logo. "Some of my older tattoos will be covered up. But I've said, 'You can't go over the Apple logo. You have to work round it'," he says.
Not many brands inspire this kind of
devotion. Harley-Davidson, Apple and Nike are among those that people regularly ink on to their skin. A quick Google search will reveal other examples such as Microsoft Windows, Google, Facebook, Dell and some designer logos, but these are relatively rare.
"People get tattoos for three reasons: love, loyalty and bravado," says Amy Krakow, author of The Total Tattoo Book and founder of New York-based Propaganda Marketing Communications. "If you're an Apple fan, you own a computer that has only 8 per cent of the market. Apple is also the most emotional brand in the world. So you have love and loyalty there."
For Harley-Davidson, another much tattooed brand, the motivators are similar, even if the demographic is very different. "A lot of bikers got them when tattoos were very out of favour. Harley tattoos play to love, loyalty and bravado too," she adds.
And the online casino Goldenpalace.com paid Karolyne Smith of Utah to have its name tattooed on her forehead in what was undoubtedly a highly successful publicity stunt.
Social changes have also
propelled growth in the popularity of branded body art. Tattoos have become far more widespread and acceptable than 20 years ago. "I know a lot of tattooists who've made so much they've retired," says Ms Krakow.
On the corporate side, people also now identify more closely with brands, in a way that they might once have identified with religions or groups or organisations such as the armed forces.
Ms Krakow adds that tattoos often signify a
rite of passage: "If you're a member of the US marines, you get a 'Semper Fi' tattoo, so if you've made a fortune in an IPO, you might get a logo tattoo."
Cory Doctorow, the blogger and science-fiction author, had a "sad Mac" tattooed on a bicep to commemorate a marathon seven-day data recovery effort.
Still, there are pitfalls. Corporate tattoos age: any MySpace and Windows XP tattoos are almost certainly looking a little passé. As Ms Krakow points out: "If you're working for a company, it might not seem such a good idea when you change jobs." Also, people's feelings about brands change.
Still, there is a long tradition of altering tattoos. As Scott Perry, a branding expert, puts it: "You could always change the RIP under the Apple symbol to read RIP OFF."