Well for starters, it is like a mini website and it's free! It can be a listing/post/blog/offer on the internet that points directly to where you want it. "Add Update" allows you to communicate directly with your customers from Google Maps and showcase what you can deliver.
By interacting with your GBP you are signalling to Google that you are an active business. Adding the update will get your profile reindexed which in turn improves your ranking. There is a caveat though, your update must be relevant, accurate and directly relate to what you offer or do. Sixth Insight can help you with your content for your "Add Update" posts.
You have 3 choices for your Update. All 3 help drive internet traffic to your Website, Socials or Campaign pages. Contact us to find out more.