I do think the online auctions work, but right now the reality of the economy is affecting everyone so people are a bit more cautious to purchase than a few years ago. They are a good marketing tool and I've been told many horses sell after the auction, so definitely a good marketing tool.
I have participated in a couple of the online auctions in the past couple of years, but in all honesty I like to see the horse or at least see a bunch of photos - cleaned up, pasture hanging out, movement if those are available. So for me to bid, I have to know the horse and the owner/breeder. I do contact the breeder (if not the current owner) for any insight into the horse as well as question the current owner for information. Earlier this year I bought a stallion off the Little Horse Barn Auction that a friend called me about at 7 a.m., Before I bid I contacted the owner for additional photos and the breeder (Getitia) and had a ton of info on him including a variety of photos of him,, his parent photos and his last foal crop photos. They both had info to me ASAP and deal was done by 11 a.m.
As for not getting to choose the home, my theory is with the online Mini only auctions, the people participating (generalizing here) are other Mini owners/breeders. Versus at a local all breed auction it can run the gambit of who is there and may end up with your horse. Not to say every Mini breeder is an ideal situation, but their reasons for buying are generally breeding/showing and hopefully they have the knowledge to take proper care of the horse. Or everyone at an all breed auction is not a good home, just a generalization.
The other thing I personally do consider with an online auction is what is the cost to ship the horse? When I'm looking at $800-1200+ to ship, that 'deal' isn't so inexpensive anymore.
But I will agree with that pet peeve on 'reserve not met' If you have a $2K reserve and start the bidding at $100 why? Just to see how high the bidding will go? If it's $2k start the bidding at your TRUE reserve price. I like a ballpark number at what the seller is wanting to make my decision to bid or not. When I see a horse that I've seen on a seller's site for $3-7K with a starting bid of $100 and a reserve, I don't generally bother as I ASSUME the reserve will be at least 1/2 to 3/4 of their sales list price if not more. So if I'm following and the current bid is still under $1K, I would again ASSUME the reserve hasn't been met yet.