Yes i have. I used to run a distribution company, so i also know a bit about it.
Think carefully before you do. A profit can be made, but the leaflets have to be VERY GOOD.
I stopped doing it, not because people weren't reading the leaflets, but because not a high enough % of the leaflets were given to people with PCs. 10,000 doors will find you 100-250 computers in a 'good to drop' area, but will get you 500-1000 computers in a 'i want to walk for britain' area.
If you do it i'd say jump in feet first, get yourself 200,000+ leaflets printed at once, get yourself a PT job with a local distribution company (expect to be paid about £20 per 1,000), and deliver your own leaflets while you're getting paid for working.
You'll get fit, and it won't cost you all that much in the long run. But if you're delivering yourself expect it to take all summer

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