If your ads are not bringing customers then there might be some mistakes in your advertising campaign. Advertising costs a lot of money and if you are not getting what you need that means your ads never got customers’ attention.
On an average there are four big mistakes that advertisers must avoid.

Creative ad of Pepsi Cola with a taste of lemon. The idea of using lemon as a character for torture and other doing is really attractive.
5 more images of Pepsi Lemon Twist Ad

After I analyzed the rejected ads I came to the end that few ad have great concept but few things make them a total rejection. Few reasons I’m going to share with you:
1. Advertisement shouldn’t include insulting, violent, offensive, vulgar, shocking and likely to cause undue distress, and misleading content for example: The Barbie fat [...]

This one seems to catch the eye of the viewer because these chips styling like tongue is tempting.
1 more image included.

Advertising Agency: & Co, Denmark.
Advertiser: BIANCO SHOES
‘Bianco Footwear you will always find the latest trends in shoes and accessories. There are styles for all types of girls and boys’
3 more images of Bianco footwear Ad inside.

Awesome creativity telling – A condom can make your death slip away. Celebrating 1st December as AIDS awareness.

The most important thing in print world advertising are:
• ‘Style of Writing’ your content which explains your advertisement beautifully. If the ad content is not interesting the ad won’t attract the targeted group.
• Try not to add images that make someone to point out discrimination, hate, nudity etc which can lead to total ban in some countries [...]