I am party to a number of contracts (website terms of service, for example), where a service operator writes the contract, and I agree to the contract by using the service. If the other party wants to amend the contract, they make available to me a new version of the contract, and the new contract is binding when I next use their services.
Intuitively, two should be able to play at this game, no? I can write up my own contract, or an amendment to the existing contract, and give them reasonable notice, and it should become binding on them if they continue to provide services to me when I request them. Under this theory, it's their responsibility to read and understand my contract, and refrain from doing business with me if my terms are not to their liking.
Is this likely to hold up in court? Or, better yet, is it likely to convince the other party to comply with my contract? Or is this sort of agreement-by-performance only binding in certain contexts, or for certain types of services? (For example, is the situation different between a web site that I browse and a service I subscribe to that sends me something in the mail every month in exchange for money?)
If in theory a contract can be amended by giving notice of terms and waiting for the other party to perform, what kind of notice is reasonable to give a large entity like a corporation? Presumably shooting off an e-mail to their automated support system would be insufficient.