In my opinion, a successful advertisement consist of a simple picture. A advertisement should not be confusing. And depending on what you are advertising, your picture may differ. However, normally, a successful advertisement should have colors that will catch the consumers eye. The colors and text should relate to the product being sold. It should also be simple and get right to the point, it shouldn't be confusing. It should also be placed in the correct area. If your target consumer is a child, you shouldn't post your advertisement in a fancy restaurant. Over all the advertisement should be interesting enough to catch someones eyes, but not to confusing. 

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