"So we've established that this is going to save you four hours a month. OK -- it isn't ready for you yet, but it will be soon. It costs $50 a month. Can I get a $50 deposit from you to reserve your spot? We'll apply it against your first month's fee."
If you've identified a problem people actually have, they'll crawl over you to give you money. You don't even have to accept it, just watch whether they're actually willing to get out the checkbook or not.
(n.b. A lot of software is sold prior to existing at numbers substantially higher than $50. For example, you might hypothetically be building something enterprise-y and looking for your first anchor customer. If you are, the conversation goes something like "OK, will you soft-commit to being our first customer on this? We'll draw up a Letter of Intent which says that, six months from now, after we've got the technology in place, we start implementing a field trial for $YOUR_COMPANY, with successful implementation to be followed by an annual purchase in the six figure region. Does that sound good to you?")