A reply to a review is for the person who left it, and for every customer who reads it after them. Forty-two percent of consumers surveyed are unlikely to use a business that never replies to its reviews, and nearly one in five expect a reply the same day.
Every reply you sign puts fresh words on your listing, which is the first place the next customer meets you. So ask for the review the moment a customer thanks you, and answer it. Your Google listing is Google's building, furnished with your words. Piece eight of ten.
The whole talk, as video and as audio: https://markheinz.com/notes/the-whole-picture