I remember when TiVo first came out. ReplayTV came out at almost the same time. ReplayTV was more expensive, but had lifetime listings included. Ultimately that proved to be a bad marketing decision, and would have probably led to the company's demise if the lawsuits hadn't effectively killed it first.
ReplayTV had already upset the networks with it's 30-second skip button, but the feature that led to major lawsuits was the automatic commercial skip.
It's a shame they didn't both survive and compete on features. I wonder what TiVo would have come up with by now with more competitive pressure?