Basically, this is how you will get your customer to buy your product, and then buy it again and again. Anyone can sell once, but how does this help the company in the long run? The simple answer is that it doesn't. For the most part unless you are selling defense systems to the government, your products are going to be fairly affordable in order to attract customers, hence the necessity for reusable products that the customer is going to need again and again.
In sales jobs, you're going to need to figure out how to do this. Let's start with a simple example shall we? There are many anti-virus programs out there for computers, and most of them work on a subscription fee. Basically you pay for the software, and then you would pay perhaps twenty dollars per month on a subscription to keep the virus database current.
This is only fair because it takes some time to update a virus database, but how do you get the customer to understand this? You cannot. All they are going to see is that you are charging them monthly for a service that they should only need to pay for once. Instead you need to show them how THEY are benefiting from the monthly subscription by showing them what was updated, what new viruses have been discovered, and how they are protected by continuing their subscription. This is one of the many tough areas of jobs in sales.
This can also be applied to many other products out there, and even if it's not a complicated anti-virus program, it could be another product or service that a customer truly needs. Whatever it is, your job is to find out how to get them to like the product, and continue buying it instead of going to another company or dropping the service altogether. Believe it or not, a lot of companies have gone under simply because they could not appeal to their customer base.
Sales employment is quite common, but getting into it is another story entirely. You're going to need to put together a resume that lists all of your skills and experience. This is a very important part of the process, and though it seems like a lot of work, you can be assured that it is. First of all you're going to need to put down your experience. Where have you worked for the past five years? Were you ever terminated from your job for any reason? If so, then be ready to explain why.
Your cover letter needs to grab the attention of the potential employer and never let go. At the end of that letter they need to WANT to read through your resume, and that gives you a better chance of getting sales employment with that company. Work hard, and make sure that you are a desirable employee. It will take you farther than you think!