Gravity4 calls itself “the world’s first A.I. big data marketing cloud”, which sounds suspiciously fluffy but is backed by some substance. They focus mostly on programmatic advertising but have “apps” that support other channels. Latest news is they’ve released a blockchain-based service for paid digital advertising. Bonus trivia: the product is called “Lydian” in honor of Lydia, the first civilization to use coins (not Lydia, the tattooed lady).