THERE’S NOTHING ADVERTISING AGENCIES like more than spending their clients’ money. (Actually, that’s not quite true. The one thing they like more is spending a weekend with a naked woman, especially if the client is paying for it and the photo shoot is in the Bahamas.)

They’ll happily blow thousands on irrelevant details, and clients will seemingly just as happily hand over the cash. Why? Because the cost of placing advertisements in print and on television is so astronomically high that the cost of the production of those advertisements amounts to just a small fraction of the total.

If you’ve ever asked to quote for an advertising job, be it illustration or music, then my recommended procedure is to think of the highest amount you can possibly get away with. And then double it. The agency themselves will stick their 15% commission on top before passing on the cost to the client, so the more you charge, the more the agency gets as well. Everybody wins.

The only problem with working for advertising agencies is that, in return for the obscene amounts of money they’re prepared to hand over, they require your soul. You start off as a creative artist, because they really, really like your style, and you end up as a mechanic moving things around to satisfy their latest whim. The upshot being that you may earn a lot, but you really do earn it.

When you work for newspapers, they commission you, you do the job, and the next day it’s cat litter. When you word for advertising agencies, they pin the work up on their wall and stare at it. After a week or two they get bored with it, and start making changes.

Back in the 1990s, when I was doing a lot of work for ad agencies, I took to making two small, deliberate mistakes in each piece of work I supplied. The rationale: they’re going to want to change something, because they don’t feel they’ve done their job unless they make changes, so you may as well give them something to change.

It makes them feel superior when they spot that a horse has five legs, or that the man in the background has a shoulder missing. And it means they’re less likely to tinker with the stuff that matters.

A common scenario when an ad agency is pitching to a new client is for them to ring up their favourite illustrators and ask if they’ll do some sample work for free. They can’t pay you, they explain, because they’re pitching for the job and they aren’t being paid themselves.

I used to agree to this, reluctantly, until one day I was at a meeting and I realised that the account executive and the creative team were all being paid, because the meeting took place during their working day. So was the receptionist, the contract cleaner, and the sandwich delivery company. The only person who wasn’t being paid to be there was me, and I was the one being asked to do all the work.

Ad agencies still call illustrators and, especially, composers, and ask them to pitch for free for work which may never amount to anything. If you don’t get the job, they rarely even call to tell you. Do the work if you’re desperate, and remember that’s why real jobs pay so much.