Sales work differently for bootstrapped founders.
You don’t have time or the resources to sell them what they want. You will need to sell them what they will buy. Big companies with huge R&D budgets can afford to sell their prospective customers a vision and then turn that into reality.
As a bootstrapper, you will need to sell what you already have. Don’t promise the world to customers just to get their money: with limited resources, you run the risk of overcommitting.
Many small businesses have been derailed by selling to just a few big customers, only to turn into their personal custom development shops. If you value your independence, go after a large number of smaller customers instead of just a few big ones.