A blitz is defined as an intensive campaign or attack. It is a short, intensive and focused marketing campaign for a product or business. Usually they happen for a very short period of time, sometimes before the launch of a new product or service, to create awareness before it is out in the market. Other times it is targeted to an elite segment of customers, where brand loyalty is already created but the purpose is to boost sales or the traffic for the company or service.
The idea behind a blitz is to have as many people as possible to get exposure to your brand. Different media outlets are used, especially over the internet, to deliver the information to the audience. Figuring out the audience prior to the blitz is key to be successful. You want to target the right customers that will take action when the marketing efforts start.