A question was asked to a LinkedIn audience: “In five words or less, what does ‘building rapport’ mean for you in sales calls?”
Below are the following answers from a salesperson, a sales leader and a leadership coach. Each of the answers displayed a common theme around building rapport and producing sales effectiveness.
Sales Person Owen shared his response, “Building rapport is all about connecting as people, not professionals.”
When asked to elaborate further, Owen replied with,“Our best sales reps are very good at getting people to open up beyond talking about business, but in a very natural way. I think there are other ways to finding a connection beyond the sales pitch. This is key. One that is personalised/unique to that person and conversation”  
Matt a Sales and Leadership Coach said, “Earning the right to investigate the client. The sales leader has to show genuine interest in the client. The sales leader must state a clear, customer-centered purpose at the start of the conversation. They make it clear right up front the conversation isn’t about them, but about the client.”  
Dennis, a Sales Leader shared, “Creating the foundation for trust is so important.”
Again when questioned further, Dennis responded with, “How have you seen people create this foundation particularly well?”
“Some examples I have experienced/observed include:
Explaining why they are calling (short and to the point).
Leaving the pitch and the features locked in the vault (depending on the stage you're at).
Asking one question at a time and retreating into an acceptance state.
Acknowledging that the sales leader is actively listening to the prospect/client.
Repeating what was said in a relevant short summary.
Showing appreciation to what the prospect/client was sharing.
Painting the picture of the "challenges to achievements" transition together with the prospect.
Saying "No" when it's obvious things are not getting anywhere or the time is not right.”
Status and leadership is reachable. 
Richard, a Head of Sales shared, “To build something stable and reliable you first have to lay a solid foundations. Trust is the desired objective but that doesn't come fast. To achieve trust you need to demonstrate credibility, reliability and intimacy whilst not displaying self-orientation (make it about the prospect/client).
Once you add those ingredients to the mix you'll have a solid foundation. Then it's all about reinforcing this foundation in every ongoing interaction you have with your prospect/client. “ 
From the answers above, I think Richard is the closest in defining rapport.
The point he makes about “trust…doesn’t come fast” is a belief. Trust is an emotion so it can be switched on or off instantly.
Now, what is done from the “trust” built, well that is the question that we seek to answer.
What intrigued me about the above answers, was very few actually articulated what building rapport means to them.
Rapport is the vital ingredient to becoming the trusted advisor.
Rapport is the vital ingredient to another person feeling comfortable to have a conversation and open up.
Rapport is the vital ingredient to being able to uncover hidden emotions around the problem AND the possible solutions.
How do you build and sustain rapport?
That is where we see most people struggle.
Yes they can do it with people ”just like them”.
They do this unconsciously. Yet when they meet a stranger (prospective client), they fail.
If you cannot articulate how to build and sustain rapport then you cannot assess yourself and add value to your prospective client/prospect.
How to build rapport?
Understand how to profile someone.
Use body language to match and mirror.
Use verbal language to match and mirror.
Ask interesting questions.
Listen and ask follow up questions.
Be vulnerable.
Be courageous.
Be interesting.
For those of you that think having a relationship is important, relationships do not correlate to being the best sales person. The top 5% of salespeople are only slightly more effective at relationship building than the bottom 10%. Click here to learn more.