You need a fast and reliable way to pass complex information to your target audience. This could be a link to a product page in an online shop, to video or audio content, or to a point on a map—among other things.
QR Codes are recommended
You are trying to automate your customer's routine action, such as sending a code via SMS to a certain number in order to participate in a promo or event, or entering a long password to connect to a WiFi network. QR Code enables instant access to any information.
Your goal is to wake the customer's interest and engage them in a marketing campaign. A well-placed QR Code can be a powerful advertising tool.