sorry to tell you this but IMO leaflets just dont work very well.
My whole business was and still is built on leaflets, got another 20,000 going out this month.
If you workOn a return of 0.3 - 0.5% you cant go wrong, price right and you got a good return.
10k of leaflets cost me £340 printed and delivered, x 0.5% = 50, convert say 40 at avergae £12.50 = £500 of 4 weekly work = £6500 per annum, thats cost me £340!!
Good return on investment imho