I have to half-disagree with this, you CAN "sell" something that doesn't exist and sometimes it's a good way to test interest and ideas.
You don't want to sell complete vapor (as in get a lot of interest then be like, oops now wait 4-5 months or whatever) but you don't want to build something that nobody wants or realize that people don't want it as badly as you thought they did.
You don't want to sell complete vapor (as in get a lot of interest then be like, oops now wait 4-5 months or whatever) but you don't want to build something that nobody wants or realize that people don't want it as badly as you thought they did.