For those who have some sort of physical presence, such as a shop or an office, which appears on Google Maps, and wish it to appear on Google Maps, because customers, clients, and contacts visit that location, then my answer to the question is an emphatic yes: you do need to use Google+. But otherwise, I think it depends on the individual circumstances.
The reason why a business with a physical presence needs to verify its local Google+ page is because it is highly visible to potential customers, as local Google+ pages themselves or information provided on them appear on Google Maps and in localized search results. In other words, it is not the strength of Google+ as a social media platform as such, but rather its impact on Google search and Maps that matters. If someone is going somewhere unfamiliar, and wants to find a shop or a restaurant for example, searching for it on his or her mobile device would be a quite likely scene. Even if someone is familiar with the area, he or she might wish to look up the opening hours of a business, just to check that the place is open before heading out. Information such as the name of the business, the address of the location, and the contact telephone number (or nap) posted on Google+ should be accurate and consistent with information on other sources.
A few months back, I met up with a friend for dinner: my friend chose the restaurant, and it was in a part of city I have not been before, so I looked up the establishment on my smartphone to guide me there. Typing the name of the restaurant on Google Maps, the pin was dropped at the exact location, so I knew where I needed to jump off the bus, and I arrived there without problem, except according to Google Maps, the restaurant had either closed or relocated. It was a good restaurant and the food was tasty, and I had to wonder how much passing trade this restaurant had been losing because of this mishap, especially when other eateries nearby had claimed their local Google+ pages and specified their opening hours as well as providing more information such links to the restaurant and showcasing their food. Just imagine, if I had wanted to eat a particular cuisine, and typed in a generic query: the restaurant probably would have not appeared as one of the local / Maps results, and even if it had, I would have shied away because the restaurant was said to be closed or relocated. When I pointed out this anomaly to the restaurant owner by showing the Google Maps results, he had no idea: he hadn’t heard of local Google+ pages.
For more information about creating and verifying a local business:
Does this mean local businesses – and in particular small businesses with one location and with a small number of personnel – have to use Google+ actively? I would argue not necessarily. Local businesses can be essentially reactive on Google+, in the sense that they do not need to post every day, follow a bunch of people or be followed by many, and engage with others on Google+ 24 hours a day, 7 days a week, except it is vitally important to respond appropriately when someone mentions the business or reviews it. Reputation and people’s perceptions of a business can depend a lot on how the business owner responds to issues, especially when something has gone wrong: level-headedness, speed, politeness, and sincerity, among others, would be qualities to show. Local business owners are not running their businesses so that they have something to post on social media, and there are so many places where businesses can be reviewed or contacted, where some sort of presence needs to be maintained: social media should help the business, not consume it. However, it would certainly help to post regularly even if not intensely, especially if something in the business changes, or there are interesting stories that can be told, such as some biographical information about the business owner, how the business started, what milestones it has achieved, etc. Many people still want to do business with other people whom they can trust, and getting to know business owners as genuine people can help in that process.
Whether pursuing a DIY social media strategy or delegating the effort to an outsider such as an agency, it will be possible to achieve a higher profile on Google+ through genuine engagement (and via other underhanded and counter-productive methods such as buying followers). Genuine engagement will cost time, money, and effort, and it must be questioned if the benefits really justify the costs. If a business is locally rooted, and the customer base is limited geographically as a matter of practicality, then having a lot of good social media followers on the other side of the planet is not really going to turn into opportunities, however satisfactory that may be, but having a small but a strong core of social media followers locally is a great sign. Whatever the composition of the followers, social media presence on its own will not be sufficient, therefore social media efforts must be contextualized and work in conjunction with other media. Other methods of connecting with the potential clientele remain extremely important: for a local business, sponsoring the local youth football team, donating to a local charity, providing something to the annual village fete, or the good old-fashioned leafleting might find far more resonance with the potential clients, than a bunch of followers from a far-away country. If the business owner could encourage people to post about the business on their social media platforms, i.e. turning customers into supporters of the business, then engagement will follow naturally, and higher profile in social media and possibly in local media.
For businesses that are not physically bound to a location, or individuals who wish to use social media in a professional capacity, it is again a question of costs versus benefits. Given the number of users on Google+, it is likely that potential contacts and clients are there on Google+, but they are also likely to be found on other social media platforms or specialized communities. If businesses and people have an unlimited amount of time, money, and effort to spend online, then all platforms and all communities should be covered, but the reality is that there are constraints hence the necessity to prioritize, and concentrate on the most effective. It is trite and bland, what works best and what does not perform that well will depend on each individual case. For some, Google+ will prove to be the perfect platform, for others, Facebook or LinkedIn.
Google+ and social media platforms in general are not the panacea for all businesses and professionals. It is easy to be lost in the deep and diverse worlds of social media, caught in the mesmerizing scene where large but entirely vacuous numbers be it followers or posts seem to signify so much, and that makes it all the more important to assess the situation carefully and decide adroitly what course of action is best suited and most meaningful in the individual context.