Pictures libraries and stock agencies are in the business of selling images. The don't give you advice on how to take better images. Their purpose is business - they sell images to magazines, book publishers, the travel industry and many other industries that use images.

Many photographers look upon agencies as a last resort to sell their work; if you have been unable to sell any of your images, the chances are that most agencies won't accept them.

If you are interested in an agency selling your images, you must be able to produce high quality images which are suited to the agencies market. Check out their website to view samples that are currently in use.

If you feel your work meets their standards and suits their customers - then approach them by e-mail or by standard mail.

But, before placing your work at an agency make a short-list of the agencies that seem to suit your work. Contact each agency outlining your work and which magazines have already published your images. If an agency is then interested they will ask you to send them samples.

If an agency accepts your work, don't take this as a guarantee that your images will sell.

Don't approach an agency until you have a large collection of images. Minimum first submissions can consist of anything from 50 images to 500 and regular submissions are normally required thereafter. Most agencies work on a commission basis - 50 % being the standard rate. If an image sells for two hundred euro - the photographer receives a one hundred euro fee.

When an agency takes on a photographer's work, they normally require a four or five year retention period. Agencies normally sell the reproduction rights of a pictures - the image being licensed to a buyer for a specified purpose.

It may take as long as six months before an agency sells a picture belonging to you. First they need to scan your images if they are submitted by film; then they need to contact their clients and let them know that there is new material available - all of this takes time, so you must look at supplying a picture agency as a long term investment. It is only when you have several hundred images placed in a library that you'll start to see regular sales.

Remember: agencies can't sell images if there isn't a market for them and placing images at an agency does not guarantee you sales.