Best way to get useful followers on G+ lately is have your people and the page active in communities and discussions. You are much more likely to get interactive people adding than just going out and following a bunch of people - anyone with a decent following isn't going to notice or react to your adding them, as they probably get upwards of 50-100 new people a day adding them. Most of whom turn out to be spam or fake accounts. I long ago stopped caring who added me on G+, or even looking!
Since communities, stream following and circle sharing matters less. So get your page to join topical and relevant communities (and if there aren't any for your niche, consider starting one if you can cope with the overhead of managing/maintaining it - nothing more offputting than a dead community), and get active in them. If your people are constantly active in the widgets communities, posting good quality info and tech help, you'll gain a lot of good followers.
However, people who've made good/interesting/insightful/funny comments on threads I'm active in, communities are likely to be pro-actively added as I've decided they are worth a try in the stream.
G+ can be a heck of a time-sink, but if you're willing to put the time in the right places it's more than worthwhile.
