Connectors are the people who "link us up with the world ... people with a special gift for bringing the world together." They are "a handful of people with a truly extraordinary knack [... for] making friends and acquaintances".  These individuals have social networks of over one hundred people. (the book was written in 2000 before social media exploded). The social success of Connectors is due to "their ability to span many different worlds [... as] a function of something intrinsic to their personality, some combination of curiosity, self-confidence, sociability, and energy." [1]

Connectors are people specialists

The following questions will help you decide whether you are a Connector:

• Do you know a lot of people?
• Do you like people?
• Do you tend to remember peoples’ names?
• Do you enjoy going to parties and meeting new people?
• Do you collect acquaintances?

If you answered ‘yes’ to four or five of these questions, you are a Connector.

They also tend to associate with other Connectors. Because of their rich network of friends and acquaintances, Connector are trendsetters. The upside of a Connector is that he or she is able to create and maintain long-lasting friendships. The downside is that Connectors can be dazzled by their vast collection of acquaintances, without investing in real friendships.

Gladwell explains:
Connector are people who link us up with the world. People with a special gift for bringing the world together.

The power of Social Media on the Internet is the power of connectors.
Power-users of StumbleUpon or Digg are Connectors. They can make or break the success of a blogpost because they are people specialists who cultivate a network of online friends. [2]

Definition of Connector
Connectors are said by author Malcolm Gladwell to be people in a community who know large numbers of people and who are in the habit of making introductions. A connector is essentially the social equivalent of a computer network hub. Connectors usually know people across an array of social, cultural, professional, and economic circles, and make a habit of introducing people who work or live in different circles.

Salespeople

Salespeople are "persuaders", charismatic people with powerful negotiation skills. They tend to have an indefinable trait that goes beyond what they say, which makes others want to agree with them. Gladwell's examples include California businessman Tom Gau and news anchor Peter Jennings, and he cites several studies about the persuasive implications of non-verbal cues, including a headphone nod study (conducted by Gary Wells of the University of Alberta and Richard Petty of the University of Missouri) and William Condon's cultural microrhythms study. [1]

Salesmen are charismatic

They are able to build instant rapport with another person and gain their trust.  That Salesmen are able to build rapport implies that they can tune in to others. But there is also another dimension: others find it easy to tune into the emotions of Salesmen. Gladwell explains that some people are very good at expressing emotions and feelings, which means that they are much more ‘socially contagious’ than others.

Here are some questions that will help you find out if you are a salesman:

• Do you find it difficult to sit still when hearing good dance music?
• Do you have a loud laugh?
• Do you touch friends when you talk with them?
• Are you good at seduction?
• Do you like being the center of attention?

If you answered ‘yes’ to four or five of these questions, you are a Salesman.

Salesmen make good politicians, spiritual teachers and pastors, and, well…salespeople. Salesmen are larger than life and can make others feel good with their high spirits. The downside of salesmen is that they can be dangerous if they use their charisma in order to manipulate others. [2]

[1] Wikipedia entry about the book "The Tipping Point"
[2] Info from Lifehack.org article
Productive Flourishing article
Escape from Cubicle Nation article