Google Plus has the potential to bring many visitors to your website, but there's just one problem. Getting people to add you in their circles can be hard, without knowing the "dirty" tricks.
Following and Unfollowing is just one trick, which is widely employed on Twitter, but it also works on Google Plus. To get good back-follow rates however, you should try to find other users on Plus, who have have already been doing this for a long time.
Back follow rates
Back follow rates can not be directly effected, but there are steps you can take to make your Google Profile stand out more, so that people may become more interested in adding you back. If you haven't done so already, you should at least fill out your profile information, and add a photo or avatar to your profile. Optionally add a few photos of your self, to make your profile seem genuine.
When you are ready, you should be on the lookout for profiles that are listed in a lot of peoples circles, and that also have a lot of people in their circles. Preferable the following number should be larger than the followers number, as its more likely that they have been using the follow and unfollow technique. Obviously the people who have followed them back, are more likely to do the same to you, if you add them.
Traffic from Google Plus
There are two ways to get traffic from Google Plus, the first is by sharing stuff directly on your profile, the other is to +1 pages on your site, which will than be shown to people who have you in their circles.
Things that you have +1'ed will show up to people in the SERPs, who have you in their circles, when they enter relevant search queries.