My favorite line to follow up on these empty complements is: "Thanks for the kind words. What do you think we're doing that is unique? What would you do differently if you were in my shoes?"
In that past week, 2 of 8 interviews have had this empty praise. Neither of the 2 could provide a meaningful example of how what we're doing is truly unique... and it is in the job ad clearly spelled out. One of the 2 hadn't even been to our website.
Interactions like these make you want to put up huge filters to weed out the people using a "resume shotgun" interview process but in my experience the amount of effort you invest in hiring pays dividends once you do hire.