The English language does not have multiple forms of addressing someone, dependent on i.e. status or hierarchy in a conversation, whereas the rest of the world mostly does. I have a long-held believe, which recently got somewhat reconfirmed by gong.io: making prospects feel at ease in a conversation increases the likelihood to close. To be specific, my theory is that in languages of two-level distinctions of courtesy forms (see map below), a less formal conversation can actually bring about sales success. Hence, I encourage i.e. German reps to push towards a 'Du' instead of a 'Sie' as soon as possible.
Distinctions in language
In English, you say 'you' to a professor and your mate at the same time. Whereas in German or French you'd say 'sie' / 'vous' (en: you) to your professor and 'du'/'tu' (en: you) to a friend. The green marked countries on the map below, show a two-level distinction: formal and un-formal. In the red marked countries, such as Japan, we have up to 5 different forms to address each other dependent on relationship status, hierarchy and age. The closest thing to this distinction in the English language is the use of honourifics such as Ms. or Sir.
Some countries are strict about the adherence to the two-level distinction, such as my home country Germany. For example, it is a big thing for a father-in-law to offer the 'Du' (informal) to the future son-in-law. It means that you have been accepted and were upgraded in the social hierarchy of the family. Other countries, such as the Netherlands, are much more indifferent about the social meaning of the distinctions and call their superiors by first name.
Making a prospect feel comfortable
Gong.io published a click-bait article in recent weeks about the impact of swearing on the success of sales trajectories.
The outcome was surprising but confirmed my superstition, if you and the prospect curse in a phone call the likelihood to close a deal increases by 50%.
No-one in their right mind would start cursing in a phone call immediately. Nevertheless, if you create a sphere where cursing feels normal, then it is a great indication of an informal and stress-free environment.
Application in two-level countries
As a German, it goes against everything that I have ever been taught to address a prospect informally - god forbid to swear in a phone call. Addressing someone formally is easy and distant. As a sales person you are certainly not making a mistake, but you are not making progress either. Formal forms create a barrier that is hard to tear down, however, an informal communication from the start is awkward to reverse. Thus, once you have established an informal tone, it will stay. I argue that the effect that gong.io showed under different circumstances is also true for addressing your prospects in an informal way (first name and informal pronoun).
My experience is that you ease the tension of a sales conversation immediately. Besides, in the two cases where people said to me 'let's stick to formal pronouns', I knew straight-away that they weren't a client fit for our SaaS product.
Remember - Nobody likes to be sold to, so why act differently in a sales situation.
My frame of reference for two-level distinctions in language is the Netherlands and Germany, whereas only Germany enforces the distinction. I'd be interested to hear whether you would share my observation in the context of other languages (i.e. Spanish or French).