A thread at the Local Search Forums has different local SEOs saying different things about how Google Posts helps their local rankings in Google Maps and local. Some say it helps, some say it doesn't help and some don't know either way.
Google's own how to improve your local rankings document makes zero mention of Google Posts. But that doesn't really mean anything.
Here are some quotes from the thread:
I would say it's worth the effort if all the other major-impact tasks are checked off the list already. We don't always do posts right away for new clients because we have more important things to do first that tend to move the needle a lot more. However, setting up posts takes very little time and effort so I'd say it's worth the time if you get even 1 conversion a month.That being said, the only time I've been able to isolate posts was this case study I did a couple years ago. I'm looking to redo it but in my experience, posts have a very minor impact on ranking.
I think the value of posts will increase substantially if Google decides to roll out this test they're doing currently.
We do posts consistently for our clients and see a marginal impact from them. The greater the frequency in posts the greater the impact. Also, quality matters. But as Joy stated, doing other activities is more than worth it.
I have not seen any rankings benefit from GMB posts. Doesn't meant there isn't any. Just means I haven't noticed it.
Have you noticed ranking benefits from Google Posts in the local results? Take my poll:
Forum discussion at Local Search Forums.