I can see how you need to protect your lists - that's a very valid point.
Looking at the big picture, I think you want to make it as simple as possible for your customers to understand and use your service. Do whatever you can to allow your customers to easily see the product, want the product, and buy the product.
Some ideas would be:
-offer some of your most simple and basic lists for free, so that customers can try it out and see how nice it is to have pre-done lists. It would be cheap for you to send them an electronic list that they can print out and try. Then you'd also have their email addresses for targeted email campaigns - before Christmas season, for example, to promote gift and wish lists, meal planning and preparing for guest lists. Springtime can promote cleaning lists, vacation and graduation party and gift lists, etc.
-offer some of your most popular lists in a bundle at a low introductory price
-do more bundling of lists to make the emphasis on how they can help solve our problems. For example, the Home Management category has 30-some lists. Break it down into more manageable groups of lists that can help me with specific tasks like for "inventory-what do you have" "projects to help you keep your house in order" "cleaning and organizing for every room and family member." Maybe sell them in bundles, with options of adding separate lists also.
-Maybe the same customer would want some lists in paper (grocery) and some lists electronic (inventory) so allow them the flexibility to do either.
It's an interesting concept! There may be others like me who don't know how much we'd value a pre-made list until we try it. Figure out a way to show us how helpful they can be. Best of luck!