I went to Google Webmaster Tools. One of my sites has a warning - "All the URLs in your Sitemap are set to the same priority". They are all set to 0.66. (On a sitemap for another site, they are all set to 0.6, and I don't get any warning. According to this Google page, "Priority" is an OPTIONAL parameter - https://www.google.com/webmasters/tools/docs/en/protocol.html#changefreqdef Why do I get a warning for an "Optional" parameter? Should I reset them all to the "Default" value of 0.5? Do I have to make the "Priority" parameter DIFFERENT for every page to make the warning go away? Or should I just remove the parameter completely? Or should I just drop the xml sitemap completely, which seems to be more trouble than it is worth? Thanks for any help. . .
From xml sitemaps generator page: So basicly, either set them manually, get a program to calculate them (A1SG or another) or don't include priority values at all in your XML sitemaps.
The only mandatory parameter is LOC. The 3 others are optional. It's however quite understandable, that if you put optional parameters, they will validate their content. When priority is all the same, you normaly get a warning. Why do you want to set relative prority between your url if it is to be the same? Just don't write this parameter and it will be 0.5 by default. Setting it to 0.7, 0.8 or even to 1.0 won't have any effect since, it is the relative priority of your pages one with another. Try http://www.webrickco.com/buildsitemap.php
Google webmaster tools will show error in sitemap if all the pages have the same priority, say 1.0. Hence set the priority accordingly. Automated tools available in www.xml-sitemaps.com will set the priority on its own.
If u are using wordpress the sitemap plugin for google may help you to set the priorities but default are best.
Outside of the url, google uses the last modified data as a key to reindex a page. If the date has not changed then Google bypasses it. If the date has changed, then it will index it. All the other parameters that are available are being used.