Everybody knows the importance of internal selling: that is selling your ideas, your projects, yourself as a competent person to your colleagues, either peers or bosses or whatever. Most of the times though, this "sales" process is not getting as much attention as it should or at least, it’s not clearly defined. We expect people to understand the importance of our work just because they are our colleagues and because we work in the same place. Most of all, we expect them to gives us their full support in whatever requests we will address them with. And that seems fair: after all, we are doing it for the benefit of the organization we’re all part of.
Many times, problems rise when your working for large organizations. They have multiple departments that span over large "surfaces": either as a number of people or even geographically, therefore, it’s often hard to meet face to face all the people you’ll need to help you in a certain project. Furthermore, large organizations now-a-days are more and more decentralized, business units managing themselves to a great extent and not always having the time or the will to respond to central requests or requests from other business units.
Your part of different projects teams, dealing with different people and depending on the requests dictated by your projects’ needs, you’ll have to get information from whatever parts of the organization. That’s when the need for a constant and efficient internal selling process kicks-in.
But was exactly makes you sell yourself internally with success? The answer is, in my opinion, as simple as this: treat your colleagues like you treat your customers: nothing less, maybe sometimes even more. Even if you worked in sales or not, you know the importance of a happy customer: positive word-of-mouth, repeated sales and so on. You’ll get positive appraisals across the organization, people will contact you with trust and your network will expand. And, as with many other things, success lies in the details. Here are a few practical tips, which people usually know but don’t pay attention to.
If you need somebody that you don’t work with every day to provide you some information, don’t just barge in and expect him or her to drop everything to help you. Instead, call first or send an email and try to set up a meeting for you to discuss properly. Carefully prepare your meeting like you would for a sales pitch. Then, send an email before the meeting, reconfirming it and attaching the agenda or some materials. People will appreciate your attention and will come to the meeting more eagerly to assist you. After the meeting, always send a thank you e-mail. This works double-way: you’ll get some more points on your "esthetics" but you’ll also be able to stress the follow-up steps and most important, the dead-lines for them.
The communication has to be flawless. I’m talking here about every form of communication "platform" you use: Powerpoints, hand-outs, e-mails whatever. Invest time in their design, make them simple and understandable. Most of all, be consistent. Adopt a style and use it (especially with e-mails – don’t assume that if the mails are internal, they can be written with spelling mistakes or no formatting or..).
Don’t be to informal to fast. Even if you call your colleagues on their first names, don’t assume they are your best friends and act like you’ve know them since always. Take it easy: build your confidence with them by acting properly and delivering on what you promise. Remember that most of times, people have to accommodate your requests in their already so busy schedules and if you don’t give them good reasons to do it, they probably won’t. You won’t get a refusal on the spot, but you’ll see that you’re not on their to do’s list when you’ll get back to them for the results – and that will be probably to late to do something about it.
Give them a good reason to help you: just because you’re nice or the benefit of the company, won’t do the trick. Neither mentioning your boss as the one that had the idea won’t: they probably won’t know him or won’t care: it’s not their boss. 
As with regular customers, put yourself in their shoes and come up with advantages form their point of view.
Another thing: mind your "shop": that is your office. In today’s open spaces, people often pass by your office. That’s an impression score you want to gain, not to lose. I’m usually against displaying personal photos and stuff like that, but that’s something up to you to decide. And also mind your top sales person: meaning yourself. I’m not going to talk about the importance of your appearance in making the right first impression: just be sure to keep it in mind all the time.
There are many other tips and tricks for you to use. I’m not going to cover them all, simply because I don’t know them all and because this post is long enough as it is now . But the thing to remember is, as said before, treat your colleagues like you’d treat your customers: invest time and attention and results will surely appear. To end with a famous cliche:we all have to sell all the time in one way or another, even if we want to or not. The trick is to make people "buy us".
For quite a while now, different public personalities(or at least their PR people) have been using LinkedIn’s Questions & Answer’s feature as a communication tool to reach the business world-wide professionals community. The recipe is simple and very effective: post a question on the Q&A section featured under the profile of public person and you’ll surely get ‘000s reactions, and along with them, exposure to the information posted under your profile. 
