@the_treeFeb 04.2005 — #Well what sever-side languages are you using? What type of database do you have? Does the coupon have monetary value, so does this need to be secure? Is the coupon for something on the site or external (like an automotive)?
@the_treeFeb 04.2005 — #Right, so you want this to be a printable coupon right? Presumably you'd want everyone to be unique to prevent forgery, so if you were using an image (I wouldn't) then you'd still want it generated dynamicaly, this can be done with some specalist software that not all hosts provide.
If you do go with that then pretty much any widely supported image format would do.
On the other hand, it would be easier just to present users with a free unique code generated some relatively simple server side scripting, probably with php or asp depending on what your host caters for. Checking for if the codes have been used already would be slightly trickier but do-able.
<div class=coupon> <div class=border> <h1>20% Off Next Tune-Up</h1> <img src="something.gif" height=100 width=100 alt="tuneup picture or logo here"> <p>Present this coupon to get 20% off your next tune-up. Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.</p> <p class=end>Good through 12/31/2005. May not be combined with other offers.</p> </div> <!-- end border --> </div> <!-- end coupon -->