Impostors who claim to be from Google (they are not) or claim to be associated with Google (they are not). They either claim your business Google+ profile is not complete, verified, or optimized or that they can raise your search engine rankings through SEO and Adwords/keywords. They spoof numbers from all across the USA to avoid being tracked and in an attempt to make you believe they are from Google (or that they are associated/partnered with Google) to persuade you to purchase their bogus services so they can obtain your financial info. They call all numbers (including cell and Do Not Call list numbers), and they hang up if you ask them to verify their identity, verify the company they are calling from, or ask too many probing questions. They are looking for an easy mark. Various reports online about this scam mention the calls originate from overseas but they spoof numbers across the US to try to make their fraud look like a legitimate US business. When they call you and ask to speak to the business owner, ask them what business they are trying to reach. They cannot answer your question because your number was robodialed, and they don't know who or what business they called.