Before John, the biggest advertisers on TV were food and drink brands whose ads were, overwhelmingly, dire. John brought his secret weapon - humanity - to produce ads of charm and wry humour, which had the novel effect of making people like the brands.
No-one was interested in Stanley Pollitt's newfangled BMP account planning until John used it as fuel. Now, even Chinese agencies are built around planning.
Despite this extraordinary talent, his focus was always on the work, not himself. His modesty, integrity and sup-reme craftsmanship provided a model. But he was a stickler for honesty with work that wasn't good enough. He rewrote endlessly, even during the shoot. The result was enormous, imaginative detail.
There would be a spot of bother if you came back to John with a negative reaction to a script, but within a couple of hours he'd be back in your office with something he thought much better, the previous one quite forgotten.
He would be pleased at all this fuss, but then debunk it and get excited about a new idea involving Gary Lineker and an iguana with a sore foot.
- Chris Powell is the director of DDB London.