Many internet marketers struggle with the daily task of finding leads(having a potential customer fill in an email form requesting their email address, or their zip code, or address for additional promotional offers to be sent to them), or a sale(having a customer complete an offer, by giving their credit card details or some other means of purchasing a product or an item).
As an affiliate the sole task is to bring traffic to publishers, and you get a certain percentage of the proceeds, either on a per lead, per sale or revenue share basis.
Now imagine the scenario, you have created a website specifically for this purpose, you designed it, did all the SEO (search engine optimisation) so it is ready for the search engines, and has all your keywords evenly distributed, and your niche is targeted.
You run an AdWords campaign, aimed at targeting that niche. Potential leads or customers see your ad with your adcopy and landing page, on google, or the Yahoo Publisher Network, or MSN Adcenter, they land on your page, are impressed with the product, and proceed to complete a sale or give their details for a lead.
This is the normal scenario for many affiliate marketers.
However there is a big snag in the pipeline, almost all publishers when using banners also place a copy of their url in the banner, so any potential customer, can if they want to simply just type the direct address of the product and get on the home page of the publisher, regardless of the work that you as the affiliate put in to bring that product to their attention, if that happens you have in effect lost time and money.
A second way many affiliates loose commissions is by simply having the direct url complete with their affiliate id appended somewhere in the url(usually at the end), all a buyer has to do is type in the url omitting your affiliate id, and they can still get to the landing page, order the product, or complete a lead and you as the affiliate would receive no compensation for the work you have put in bringing that potential customer to the publisher.
This is where url shorteners, or url redirection comes in as the potential customer never sees the direct landing page, or your affiliate id inorder to go directly to the publisher, and hence denying you of your commissions.
There are several types of url redirections, some may require registration, some may not and you can easily test out the different types to see which one would suit your traffic, some may have a delay of a few seconds in other to show some ads before going direct to the page of the url redirection, others simply go direct to the shortened url.
Once a shortened url, or url redirection is created, this unfortunately is not the end, as often webmasters redirect shortened urls continually so constant checks must be made to see if the shortened url is still active, and your shortened or redirect url has not been sent elsewhere.