If you advertise that you have the best prices guaranteed in your brochure you need to make sure that is what you have as it is easy show that your prices are not the best.
A newsagent showed me a brochure today from a competitor, another newsagent, with prices that are not the best yet to makes the best prices claim.
Customers who respond to the best prices claim are price conscious. Many will price check and the claim will soon be found to be what it is. The others who don;t price check and end up paying more will either keep being duped or soon enough realise their mistake.
The ACCC advises businesses to ensure that claims in advertising are accurate. The claim in the flyer I saw today could have been easily checked prior to printing. Such a check and consideration of the ACCC guidelines would have seen the flyer not printed in its present form.
Be careful, do your homework, make sure your claims stack up.