women talking at workGvahim/FlickrHere's how you can persuade colleagues without manipulating or exploiting.

We're all in the business of persuasion.
We're trying to persuade bankers to give us a loan, the boss to give us a raise, or the family pet to come inside after busting out of the front gate. Almost everything you do at work or in your personal life involves persuasion.
Sadly, many people use techniques that are totally ineffective.
We command, we cajole, we con. Those tactics are the opposite of persuasive. They destroy business relationships. They're selfish and rude. They don't work. They leave you feeling unfilled and miserable.
Most of what I've learned about convincing people to "see the light" and become more helpful or agree with an idea has come from my wife. She is a master. My only regret is that it's taken me so long to learn some of her tactics. And the first lesson I had to learn is that they are not tactics at all. She is just being genuine and sincere.
It's not a matter of trying to "sell" someone but of coming to a mutual understanding of need. That's true persuasion.
Now, for the tips.

1. Always tell the backstory.

Again, I'm learning. Slowly. I used to think leadership, work relationships, and just about everything else in life were all about being the one who makes the commands. Oops. What I've learned is that you have to give enough details and backstory. People want to know why you are asking them for something. You have to be honest and real about your request. There is a reason why you need that business loan.
Getting all hot-headed is not going to help. When your phone breaks, yelling at the Sprint agent is not going to get you anywhere. Explaining that you have an important meeting coming up, that you are a little stressed out because of a problem at work, and that you just need to get a working phone is a better approach.

2. Learn to have patience.

Some things are worth the wait. Sometimes, getting what you want is just an exercise in patience. Don't give up. If it is something you really need or want, just learn to set aside some of the urgency and figure out a back-up plan while you wait. Now is a fleeting moment.
The urgency you feel might not be as important as you think in the long run. The real benefit to learning patience is that you become a patient person and people can live with you. You exude a sense of confidence and calm, and that encourages people to meet your needs.

3. Focus on the relationship.

This one might require a twist in your thinking. Often, what we really want is to have a good relationship, both in business and in life. You think you want that new contract worth $20,000 but maybe what you really want is a relationship with that new customer who will pay you $20,000 every year for the next two decades.
You might need to shift your wants. In many cases, developing a good relationship — with your employees, co-workers, investors, and customers — is the most important outcome of persuasion, not a bigger paycheck.

4. Stop demanding and cajoling.

Some of the most miserable people I know have this attitude about persuasion that it's all about cajoling others. You try to trick them — usually through a stern attitude or a demanding voice — to get what you want. It doesn't really work, unless "what you what" is the same as feeling miserable.
The biggest jerks you will ever meet are always trying to cajole others. Yet, those who are actually getting help and finding fulfillment, the people who have real friends, are not demanding or cajoling at all. They are friendly, polite, unselfish, and kind.

5. See the bigger picture.

The best way to get what you want is to see life as a marathon, not a sprint. In the end, what you want is true fulfillment, relationships that are rewarding and engaging, some peace and calm amid the constant chaos. You walk in to buy a car and start berating the sales agent to give you a good deal. Maybe you even get a good deal. But you have ruined his day and acted like a jerk. No one likes you.
Now go to the same dealer and just get a fair deal but act like you don't even need the deep cuts. Suddenly, the agent treats you with respect. You feel good about how you acted. Your kids see someone who is fair and pleasant. That's the big win.