Increased and new foot traffic on your property
By giving their product away 7-Eleven will definitely have had increased foot traffic in their stores. They will also have people who don’t normally go into a 7-Eleven store just because they are having this promotion. If only 10% buy something else they will make the money back what they are investing in this.
Giving something away will result in people coming who never normally visit you. Once they are at your property help them to become a repeat visitor and give them another reason to come back. In business you may be have another special offer. In the non-profit world it may be an invite to an event or an initiative that they may be interested in.