Marketers tend to spend money on advertisements that look impressive but fail to generate actual sale. This can be avoided by spending wisely on what produces the greatest output. I follow a 70/20/10 formula, in which 70% will be allocated to campaigns that have already been tested and proven to be effective, 20% will be allocated to small modifications of those campaigns and 10% will be allocated to bold experiments. This way spending is protected while having an allowance to try new ideas.