Not speaking legally so you will need to check the rules on how you can do this. But in shopify you can just setup your payment to be captured manually. So they "order" and you have to manually click to charge their card. Opposed to how it auto charges. They will have their card preauthorized for the amount, you are just making the final decision to charge.
In admin>payments drop down. Go to Order Processing and the first one is "After an order is place" you will see what I am talking about
i do pre-sales quite often as we run out of stock so it's more like a reserve. basically you'll just have unfulfilled orders and yeah you could not authorize the full charge but i usually do, but check the law on this as i might be on the edge there.
i will say that with fulfillrite as my order fulfillmment house they have no trouble with pre-orders or back orders, it gets marked as such.
Yeah that's probably a good way to go. I do make it clear to all that we are shipping the good later but I know there is some time limit on how far ahead you can take people's money. Then again I think it also comes down to treating people right, so long as I'm not scamming people no one bothers to enforce a law like that. Anyway the real thing is to get your stock coming just in time, I'm working on that. Funny that there are laws on pre-orders but you can take people's money on Kickstarter for many months before you deliver anything.
Pre sales can be a great achievement between you and your consumers as it shows confidence of a popular product out of stock but you wanting them to have it by making arrangements for when it is available that they can be placed on a list for it.
When a client sees that you remembered them over a transaction that might of only taken a second it gives a lot of faith to that person in your company.
Pre sales however can also be disastrous without attention to detail and a fair amount of following up as clients can be added to this list from 10's to 100's depending on popularity. Which can be another reason why sometimes its not seen with all companies.
If you have the passion the client will be quick to see it. Its a huge edge these days.