Desert Fox wrote:What I'm not clear on, is cases where the promisor doesn't actually benefit, but the promisee is harmed. Like paying someone to run 20 miles.
I think the Hamer case basically stands for the proposition that the correct standard is "legal detriment," not "benefit." It didn't matter if the uncle benefitted because the nephew suffered a legal detriment either way. Both parties must suffer a legal detriment to constitute consideration, and courts will typically not inquire as to whether the parties benefitted from the contract. Indeed, many contracts are "losing" deals for one of the parties.
Edit: Now that I think about it, the Hamer court discussed the benefit to the uncle. Perhaps it was later case law that made it clear that legal detriment is the proper measure of consideration.