Is it ever a bad idea to publish a sitemap for a blog?

I have a blog, and I have been considering publishing an XML sitemap for it, which would include the index page, archives page, and an entry for each individual blog post. Is this ever a bad idea? Is it a good (or useful) idea? I'm particularly interested in the <changefreq> element: I edit posts from time to time, and while that's not a common occurrence, I don't want to set a particularly infrequent change frequency that p开发者_如何学Crevents search engines like Google from indexing the edits. (The XML sitemaps protocol says that search engines may still crawl the pages more frequently, but has no further details on the matter.)

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It's almost always good idea to publish an XML sitemap.

You can leave out the changeFreq element and accept the default if your web hosting can handle a reasonable crawl rate from the search engines. If you're already being crawled, you should have noticed any problems by now.

Add your sitemap to Google webmaster tools and you'll be able to check for any crawl problems, unreachable pages, 404s etc. Very useful.

The only reasons I can think of for not adding an XML sitemap are if your site contains a lot of duplicate content, broken links, empty or hacked pages. Fix those issues first, then submit a sitemap.

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I have web sites with sitemap and sites without sitemap. I can't see any real difference in SEO. Google seems to decide the optimal frequency independently of changeFreq so it is almost of no importance. There is a setting in google webmaster tools for crawler visits on the entire site. When I use sitemap (Wordpress Plugin) i use default settings for changeFreq that are: daily - for blog page and blog posts. weekly - for categories, static pages. always - for main page.

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I use XML sitemaps on all of my blogs. If you are using Wordpress this plug-in does all the work for you: http://wordpress.org/extend/plugins/google-sitemap-generator/

It will generate new sitemaps every time you publish or update a post.