You should assess the quality of mares and not reject them for registration or lack there of, but for the standards you wish to produce in his progeny. Advertising is an important aspect of promoting a stallion. Ads with a photograph will be more likely to get attention than plain text ads. Printed brochures, magazine ads and show pamphlets are all methods of keeping your stallion in the publics eye, but can be costly. You should use as many types as you can and still maintain your budget.
Internet advertising is often very cost effective.
Unlike the printed media it is very easily updated and can be used in conjunction with the printed media to elaborate on your stallions qualities just by putting the URL in any printed ads you run. You MUST have a clear, flattering photo of your stallion to show his good qualities. It is best if the photo has a muted background, even if the horse is in motion. You don't want prospective customers distracted by the background, you want them to focus on your stallion, then pick up the phone, or click the mouse for further information. Keep your description brief as can be and still capture the interest of those you feel who are the most likely to wish to use your stallion for breeding.