Sorry, I guess I didn't say that right. I meant that you shouldn't charge for things that customers have the perception of being free to you. People don't seem

Sorry, I guess I didn't say that right. I meant that you shouldn't charge for things that customers have the perception of being free to you. People don't seem to like that. A customer will think "Oh, more invoices if I pay X dollars more!" and that's tangible. Those are physical invoices stored somewhere. But when you try to charge for something stupid like the ability to change colors or something, that seems to make people angry. I've done user testing with payment tiers, and whenever someone asks "Why does this cost more? That's stupid" they immediately have a bad taste in their mouth about the product. And that's a first impression before they have even started to use it.