My relationship with MountainTop Data goes back years and started a few companies ago. I have used many list providers in my position as VP of Marketing, as we are a power user of marketing automation systems, and I have never found any other company which is as responsive, thorough and cost-effective. Working with them is a pleasure – my account manager is always direct, on point, asks the right qualifying questions, and then gets the job done. MountainTop Data is my go-to provider for lists, and now we are trying them for data augmentation. 5 thumbs up.