Here’s the case of a troll that tried to get royalties from all on-line retailers for the Shopping Cart. Actually sued, and for some time won, for a percentage on all sales passing through those carts – that has to be huge money.
Now this particular troll has lost a big case, invalidating its previous big wins. Any guesses how much was consumed in legal bills and related costs for its various lawsuits, before the dust settled?
Software patents have two functions: they allow big businesses (the ones with patent portfolios, and pockets deep enough to retain intellectual property lawyers as needed) to increase their market power at the expense of small operators who lack those resources; and they provide a living for pure rent seeking patent trolls, and of course the IP lawyers on all sides of these disputes. Big business tends not to like the second function of software patents, but values the first. For the rest of us, they’re both dead losses.