One would expect an easily pirated version of a product to cost more than a protectible one. TurboTax pricing offers a nice example of how this works with software.
“Shrinkwrapped” software that runs locally on your machine is easy to copy and give away; it’s a non-rival good which is largely non-excludable. “Online” software, which runs on a server and is accessed over a network, is easier to protect, since it is never distributed. It is both rivalrous and excludable: all users have to share the same pool of server-side resources, and the vendor can decide who can access the software.
It’s not quite as simple as this, since the seller has other reasons to encourage purchase of the Online version, like customer lock-in through holding their data on the server, and the desire to promote a new product by offering discounts.
We see something similar occurs in the digital music market. Music is another intangible good that can either be downloaded to run locally (eg iPod/iTunes) or streamed from a central server (eg Rhapsody). There are more differences between the product offerings than in the TurboTax case, but the trend is clear. Rhapsody offers unlimited streaming access to more than a million songs for $10/month; if you want to buy and keep a song it’ll cost you almost a buck each.