Does the world need another way for brands to give online influencers free stuff? Australian social-marketing company Social Soup hopes so: it's been testing new in-store voucher tech with a big client: PepsiCo.

The technology revolves around Social Soup's app for influencers, which they can now use to scan certain products in stores, and get an instant voucher to redeem against it at the checkout.

The test campaign focused on PepsiCo's Sunbites Snack Crackers, with 2,000 influencers accessing the voucher, and in turn posting about the snack on their various social networks – for example, on Instagram.

Social Soup recruited the micro-influencers, and says the campaign's ultimate reach was more than 1.2 million people, exceeding all its targets.

"With our voucher delivery system in the Social Soup app we know when a customer has the product in their hand and we can deliver them a voucher to redeem at the checkout," said CEO Sharyn Smith.

"This is a game-changing process that allows us to know where the customer is and track their full experience journey with the product and get feedback. Ultimately we can also reward them for sharing in social media which provides authentic influence from a real experience."