I also used to 'boost' my high school senior posts to other 16/17/18 year olds in whatever area they're from. Not only did that work as advertising for me, all of the likes that the images got from that probably really boosted the kid's self esteem. Within the past year they made it so that I can no longer target people under the age of 18 by area.
Because you had the money to advertise, they wound up exposed to your photos; they liked them and they were able to afford you, so they booked you.
However, the cost of your services necessarily accounts for you spending money on advertising. Someone who doesn't advertise may have had the same quality and style of photography and a better price, but because of your advertising, the couple were tricked out of finding the best vendor. You distorted the wedding photography market in your area, and your customers actually got a worse deal than they maybe could have.
Or, perhaps you are actually the best photographer in your area, and no one else would have come close for that couple. You still lost money because you paid for advertising.
Even worse, someone who is worse than you at photography may come along with a huge advertising budget and become the only visible photographer in the area, scamming both you and the couple from a better deal.
If instead there had been some open local directory of wedding photographers, which may charge some fee for services but otherwise present all phtogorpahers neutrally, the couple would have still found the best deal, and you would have been able to either offer lower costs, or made higher profits.
Sure, but that would only work locally. I do weddings all across my state. Couples would also have to look through pages and pages of terrible photographers. Those photographers don't have the money to advertise because they're bad at their jobs and don't do it frequently.
Yeah, in some ideal world people would be matched up with whatever product/service is best for them all of the time. We don't live in a perfect world. People won't buy what you're advertising unless they think it's a good fit for them. Because people buy whatever you're selling, that means you can keep advertising, which means the stuff advertised tends to be what people want to buy. Right now that's the best system we have. Any other system right now would probably be like when you search for things on Amazon nowadays, absolutely riddled with cheap Chinese knockoffs.