I post several times most days. I don't get any more than a few 'likes' but IMO Google Plus is more than just the social platform, although it always seems to be compared to FB. I use the G+ share api on all my pages and occasionally see that someone has shared my page.
When I post photos, memes, links etc, they get scraped and reposted at many other places on the web. I see it all the time. It's a good place to broadcast.
But most important, Google Plus is basically your Home Page for other Google accounts. It helps verify who you are for other Google platforms such as Google My Business (formerly Google Places) and Google Maps locations. If you like/review an app from the Play Store, review a company that's listed on Google My Business, your Google Plus profile photo & link to your G+ page are displayed as well.
I think if you want to see immediate results as far as 'likes' on Google Plus though, you need to put a lot of effort into creating & maintaining Collections. That seems to be where the numbers are.