Just general advice: You want the cost to explore and adopt to be low. You want the revenue of a retained customer to be high. Unlimited pricing is a good sa

Just general advice: You want the cost to explore and adopt to be low. You want the revenue of a retained customer to be high. Unlimited pricing is a good sales tool when it helps minimize brain damage for your customer. They will over-value it if trying to figure out every possible use is scary, or difficult. In other words, it gives them room to experiment and uncapture hidden value (for them). What you need to keep in mind is whether or not paying for this trial and error usage makes any sense. In other words, are they exploring your service? If so, they are likely finding value that once discovered they will be willing to pay a reasonable rate for. On the other hand, if they are exploiting you, they are just farming out their costs to you and this will never end (it always makes sense). So, try to figure out why they want to stop. If they threaten to stop becuase of the brain-damage/experimentation issue,,,try to find a way to work around that. If they simply feel your service is simply un-economical priced any other way, you may want to expore that more carefully. In this case, you may have a bigger issue on your hands. This gives you some frame work to think about features. Features which are necessary to explore vs features which allow simply "power usage". May want to treat those features and those stages of using your product distinct.