O2 and Millies Cookies gave away more than 500,000 free biscuits in September as part of the operator's Priority Moments scheme, which they say reaches 22m customers everyday.
50,000 pairs of flip-flops were also given away during the Queen's Jubilee, heard the audience at the Guardian Mobile Business Summit.
Partners who work with the scheme were said to see their basket value increase of 25 per cent and conversion rates, those deals that are redeemed, are up to up to 95 per cent.
"At a minimum, redemption rates are between 5-10 per cent, but that is 10 times better than direct marketing," said Mark Stevenson MD of O2 Priority Moments.
“I don’t think we’ve touched the sides with what we can do - us as a brand, for our partners and for our consumers.”
Next year, he said, O2 would see more more refined targeting, along with cleverer offers that know exactly where users are and that harness the power of what they’ve used in the past, and what they haven’t.