For those who are not users of Google+ or have just started, Google+ is a social medium in which you connect with other people (Google+ profiles) and things (Google+ pages), and you organize whom and what you follow by adding them to your circles. The circles can be named in many ways, such as your family members, close friends, friends, acquaintances, business connections, interesting pages, news sources, etc.
Once you have organized people and things you follow into circles, you can share your circles containing the profiles and pages you have added with others. For instance, you might add a bunch of Google+ profiles and pages related to your hobby into a hobby circle, and you decide to share that circle, because others who share the same hobby may be interested in following the Google+ profiles and pages you follow. Conversely, someone else might share his or her circle with your Google+ profile or page among its members, because you have posted frequently on Google+ about your hobby and that person has noticed you. Such sharing of a circle could be very useful, since the members of the circle are editorially selected with a well-defined purpose. It is a good way to discover other interesting Google+ profiles and pages. While Google+ communities are a natural place of those who share the same interest to congregate, there is still a lot of merit in following Google+ profiles and pages.
There are other uses of shared circles and one among such has been at the centre of some debate. To put it bluntly and somewhat unfairly, as it is setting fire to and then knocking down a straw man, there is a type of shared circles for the sake of sharing, and whose aim is to increase the number of followers. In other words, it is a mechanism to gain more followers to make a Google+ profile or page look more popular. Unlike purchasing followers of dubious provenance from dodgy sites, there is therefore often an element of lop-sided, unequal trade-off. In return for being added to an amorphous and editorially meaningless circle purely to make up the numbers, you will have to add the circle master and other existing members of the scheme to your circles, or otherwise do something that the circle master thinks is of value such as +1ing the post. In many cases, it is basically a Ponzi scheme of followers: so if you are going to get into this game, it pays off to be in it early.
For some people, the followers represented in numbers are everything: the illusion of popularity created by numbers is translated magically into a convincing authority to target the poor gullible marks. For some marketers, or someone who in the future wishes to monetize his or her influence, these numbers are important, as they are easily quantifiable and marketable, making it possible to claim a potential reach of x number of people as represented in the number of followers. That is all good and well for them, but what does the number of followers mean to you? Does it really matter how many Google+ profiles and pages follow you? I mean really? There is material interest for some people to increase the number of their followers, yet for you such incentives may not exist, except for the empty satisfaction of an illusory audience.
If you seek validation or solace in the company of many spammers, would-be scammers, and desperate marketers, as well as the clueless and the gullible, or merely the confused and the enthusiastic, that is entirely your choice, but by adding them – a random collection of numbers-chasing Google+ profiles and pages – to your circles, your experience on Google+ is likely to become poorer for it. Even if they are not spammers, scammers, and marketers, adding Google+ profiles and pages with which you share nothing in common, the quality of the posts you will see on Google+ is very likely to suffer, in that you will see things that are of little or no interest to you. I would argue further that there is potential in future that your online experience, if at all connected to Google, will be generally poorer. For this reason, in my opinion, and it is my main contention, that you ought to be careful and exercise good judgement regarding whom to add to your circles, such as when circles are shared with you.
While you cannot control who follows you, you can control whom you follow, and the Google+ profiles and pages that you follow will determine what you see on your Home stream as well as in the What’s hot stream (which incidentally I totally ignore). The Home stream is the default stream where you see posts from other profiles and pages that you have added to your circles, as well as posts that they have recommended by the means of +1s, alongside your posts and posts in the communities you have joined, and what appears on this stream is determined by Google algorithmically. In other words, you are likely to see lots of spam, if you have added spammers to your circles, as much as you are likely to see lots of landscape photography, if you have added landscape photographers to your circles.
The following is purely speculative, but I think it would be a fair assumption (though an assumption nevertheless that may turn out to be false) based on what Google has been doing thus far with Google+ and connected products and services: it is likely that the recommendations such as +1s, share, and reshares by the connections that you establish on Google+ will influence what Google recommends to you, in suggesting YouTube clips for you to watch, in recommending businesses on Google+ Local, or in providing personalized results when you search for something, whilst you are signed in to your Google account. Marketers and advertisers can thus affect and even manipulate what you see on Google+ and on the wider Google landscape subtly, where the lines of editorial content and advertisements are going to be increasingly blurred and well nigh impossible to see at all. Even if any endorsements obtained in exchange for payment should always be declared, such would be difficult to trace, when diffused through +1s, shares, and reshares, that influences what Google+ users see in their streams.
Perhaps another way to put this issue is thus: what you see on your Google+ Home stream is a reflection of whom and what you have added, and indeed what you deserve: if you do not like what you see, then I would look into your circles, asking why you are following the Google+ profiles and pages that you find there (as well as ignoring What’s hot). There are many questions you can ask yourself when pruning your circles. Are these Google+ profiles and pages posting things that I am interested in? Do I value what they post? Do I wish to engage with them? Do I trust their judgement? Are they interested in me at all except as a number? And perhaps most fundamentally of all: why am I following this profile / page?
My contention can be boiled down to: do not become just a number in someone’s Google+ profile or page, or chase numbers on your Google+ profile or page, if you are after quality engagement on Google+. Be in control of your Google+, by choosing to follow other Google+ profiles and pages because you find them interesting, insightful, useful, enlightening, funny, etc, viz. for a good reason.