You must design creative strategies and tactics that will cause the targe

You must design creative strategies and tactics that will cause the target public to choose to perceive your messages, choose to retain them and choose to act upon them. 

A “big idea” is a creative, overarching strategy and message that appeals to all publics you will target. Describe your big idea in one sentence. Then include a bullet for each of these three components: 

• Big Idea Strategy (100 words min)
• Big Idea Message (100 words min)
• Big Idea Visual representation of the idea. For the visual representation, you can submit a visual idea (an actual graphic, drawing, etc. or you can describe the visual if you prefer. (100-word min explanation if you do not include a graphic. If you include a graphic, please explain in one or two sentences).Think outside the box! 
• What's your slogan? The slogan encapsulates the big idea message and strategy. 
• Big idea in one sentence?  Describe your BIG IDEA in one complete and concise sentence.

Here are a few tools to help you 

Four steps to developing a big idea for your campaign [belVita Case Study] | Smart Insights 

The following are five suggested questions to ask yourself when working on your big idea: 

1. Did it make me gasp when I first saw it? 
2. Do I wish I had thought of it myself? 
3. Is it unique?
4. Does it fit the strategy of the product? 
5. Could it be used for 30 years?