One of the ideas that we discussed early on was the possibility of charging a base price B for access to the asset, plus a per-title fee T for shipping it in a commercial product (so you’d ultimately pay B+n*T), with the option of B=0. Another idea was having each game ship with a “bill of materials” and the ability to charge a small royalty for certain Marketplace items, adding to the engine’s base royalty, or monthly fee. We put a lot of thought into various approaches to constructing a Marketplace economy, but from the perspective of buyers deciding whether to buy an item, the simplest unified terms were always the most compelling.
My suggestion is to try to estimate the average number of commercial products that will be shipped by a Marketplace buyer of a high-quality, reasonably-priced item. Given that many folks are enthusiasts and tinkerers, the number may be less than 1.0. If we only count users who ship at least one commercial game, let’s guess 1.5, since each developer is trying to satisfy his customer base by shipping new, original games, and that limits content reuse. A small number of developers might ship many games with the item, but on the average they’ll be offset by the 1’s.
So, if we offered that choice, it might more realistically be between $50 for a per-title license and $75 for a lifetime license. But if all Marketplace licensing is generously lifetime across-the-board, and Marketplace buyers can buy with confidence that they can use all items forever and without concern for relicensing, we think the overall opportunity for all sellers will be maximized compared to offering more complicated choices of terms.
That’s the theory anyway!