When you think influence, think in terms of three. Not necessarily the Three Stooges, but the three categories of people who can make or break any influence attempt.

As we all know, when influencing, it's not always clear who all the players are. The person who ultimately gives you the green light is the obvious one. But what about those behind the scenes who, if not in the loop, can thwart even the best influence attempt? That's why when you think influence, the Moe-Curly-Larry mindset applies. Here are the three groups to consider:

The SELL Group. This is the obvious group that never gets left out -- the decision makers who give the yes or no to any request and the ones to whom you address your compelling pitch.

The TELL Group. This is the group that often gets left out. These are the people who want to make sure they have their hand in what's going on; they like to be kept in the loop. TELL is the political category, and keeping them apprised is often a smart and strategic move. Although they may not be the final decision makers, if they're not connected in, they could take it as a slight. And if they do, they then could join a campaign, conscious or not, to thwart you on this or future requests you might have. Always keep a list of these "need to know" people -- those who could help or hinder you now or in the future, and put them in your TELL group. Your boss, no matter what level you're at, is a likely candidate for this FYI group.

The HELP Group. The third category has the names of those people you need to enlist to help you in the influence process. These are the well-connected, well-respected people whose help you might need ahead of time before you pitch to the SELL people. We're not talking just anyone here. This is a list of people who could sway the decision makers.

Take a few minutes to think about an important influence situation you've got coming up.

1. Who's in your SELL group -- that is the person or people you need to influence directly?
2. Who's in your TELL group -- politically-speaking, those who should be kept in the information loop about what you're doing?
3. Who's in the HELP contingent -- those who can assist you in selling before, during, or even after your actual influence attempt?

Denise Brouillette is the president of The Innovative Edge LLC.