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I think you have a good grasp of the pros and cons, some points I would like to add I would not be too worried about the 301 redirects; they will leak a bit of link juice but not much. You will get about 85% or more on the link juice. The url-rewrite .asp to aspx method will stop any leak,  but I just don’t like the idea of having file extensions, aesthetics are important to conversion. But I like method 3, for the reasons you list. File extensions are so yesterday.  I think extension-less URL’s are better for conversion What you don’t want to do it revisit this question next year or the year after, you need to make a choice now and get it over and done with and move on. I would of maybe looked into ASP.MVC that has no file extensions at all, and I believe is the future of ASP, but it looks like you have already gone past that point  in the decision making One more point, if you go with method 3, decide if you are going to have a trailing slash or not and stick to it in all your linking. Myself I favour the non slash as people hand writing links are unlikely to add the trailing slash, leading to an un-necessary redirect. Good luck