"want to have a company's registered trademark and/or logo tattooed to them for the rest of their life"
It was discussed a bit earlier, Bedders.
My own thoughts are that people (including myself, from the outside) see the MDot tattoo as a badge of achievement rather than as a logo. Of course it IS a logo, but it's more than that - it's a brand, in the true sense.
And in marketing terms, yes, a spectacularly successful bit of branding if people do see it as a badge of honour/achievement.

erm...I wouldn't mind a closer look at the Olympic Rings (another brand) that Chris Hoy has on his upper arm... ;o)