For sport horses,
Things I like in an ad:
Breeding, if there's a place for a bloodline "tree" I want it all filled out and if there's not - I want to see one on the introduction of the video (back to GGsires)
One good conformation picture, the horse should preferably be braided and no tack or wraps except for a clean bridle.
Pictures (4 to 5 max) of the horse undersaddle with a good rider, I don't want to see a 5 year old walking on the horse, I want to see a clear picture of "the best" that the horse can be.
On the video I want a concise video under 5 minutes. I want to see in the introduction, the name, DOB and breeding of the horse. I want to see a clear video of the horse walking free, walking on a rein, trotting both directions and showing any GOOD lateral work they do (I don't want to see a horse thrown into a shoulder in for a sale video and done poorly), cantering both directions same thing if they do simple changes or flyings, show it but don't show bad ones!! If you are claiming it jumps, either jump it or show it going through the chute MAX twice, and at the highest height only. If you are claiming the horse hacks out, show a picture at the very end of the horse outside with a rider on it, otherwise a liberty or conformation photo with your contact information over top. The video should be at most 5 minutes long.
And finally a concise description of the horse including, DOB, height, breeding, training, reason for selling and any sale conditions. I don't want to read about all the things the horse would be great for - I can determine that myself.
What I don't like:
If the horse is broke, don't show me it running around in a field or arena, don't show me it lunging. 99.9% of horses can do both of those things. If it's a baby, they are acceptable but dedicate a videographer - I don't want to hear you clucking!!
"Fluff" pictures - while it's awesome the horse gives kisses, I don't want to see pictures of it on your sale ad and then none of you riding it
If it's a riding horse, there should be pics and video of it being *suprise* ridden! If there's only room for one pic, I want to see an action shot, with a rider.
Long, ridiculous videos. I know the horse trots, don't show me that for 3,4,5 minutes straight. Think about a dressage test - that's what I want to see!
Doing bad "tricks" just for the sale video - just do what you would normally school.
And I think that's about it.... I look at way too many sale ads!!