I'm currently adding a URL rewrite module to a forum to make the dynamic URL's SE friendly. The problem I have is that the nature of the subject means people are tending to post threads with titles of 20 or more words. The rewrite module will end up giving me page URL's hundreds of characters long with 20 or more hyphens. While theoretically these should be readable I'm wondering if they might be too long for search engines to index? Does anyone has any experience with very long URL's, and do they help or hurt your seo efforts?
I have used such long url previously. And such long URL will hurt your SEO and SERPs ranking. Never use very long URl dont make it longer than about 75 character.
John C. Dvorak said: "Now don't get me wrong. I'm not saying there's nothing you can do to get more attention. Much of what you can control is structural. If you have a blog full of fancy AJAX code, it's going to be difficult to index, for example. Making your Web site search-engine-friendly is one thing, in other words. But using stupid human tricks such as the long URL and tags to get more attention is folly—and bad advice, from what I can tell. Beware!" You can read this article: SEO Fiascoes: The Trouble with Search Engine Optimization on pcmag.com
As with everything when it comes to SEO, it depends. In general, it doesn't matter when it comes to getting indexed by search engines. The would penalize you, though, if you long url looks like you are engaging in stuffing keywords into the url. Keyword stuffing in any aspect of your site will get you knocked know a couple notches. Given that, shorter would be better. Also makes it easier for humans to read.
In my opinion it is bad of course. The more keywords the less is the weight of each kwd, that means by simple math that any new blog with normal short url structure will outrank your site on page by page basis.
using long urls is not a good idea as it will hamper your rankings in the search engine and traffic to your website