Chris Anderson’s The Long Tail really got some Web ideas percolating in my brain. Example: The importance of user ratings to all sorts of mega-sites, from Netflix to Amazon. Netflix, though, could improve its reccommendations a bunch by having combo ratings for couples and families. As far as I can tell, although my wife and I can both rate movies, the system doesn’t calculate films we’d both like. Since we usually watch movies together, that’s really a key for us and, I suspect, for other couples and famililes. It’s great to find a film everybody can watch. The trick is not just offering such combo ratings, but calculating them smartly. Can’t just average two ratings — my 5 stars and her 2 for Kill Bill doesn’t equal a 4 and a 3 for, say, Big Mama’s House. No, you have to treat those 1’s and 2’s as vetoes, or favor pairings with the highest lower number.

Further, think how much ratings could benefit all sorts of other sites. Know of any blogs where people can rate posts? (Most visited and most linked are good, but not the same — they can miss buried treasures.)  Them imagine a blog network where such ratings are collected, let anyone’s great post bubble to temporary stardom.

Google itself needs a ratings system. Its over-reliance on counting incoming links means stale and outdated sites linger beyond their usefulness. New negative votes would knock down aging or outmoded sites, boost upstarts with the latest information.

Same for newspaper Web sites. Every day great writing is bound to get lost. A so-so headline or a suspect subject can help stories and blog posts slip and slide from sight. “Most popular” or “most emailed” are helpful, but doesn’t help “the long tail.” With ratings, a single five-star can pop something into special list, where other might find it, link it, and turn obscurity into a rewarding discovery for thousands of people.