I used to update my sitemap fairly regularly, at least several times per month. Now I just don't have as much time as I used to. When I do get around to it there are many new links which should be added that I don't have a lot of time for. I came across a free php script which I can integrate that will automatically create and add the link each time something new is posted to the sitemap. It stores it in a database, but it is supposed to be compatible and work fine with search engines. The free version does not allow for any lastmod, changefreq, priority, etc tags. Are these additional tags extremely helpful? Not at all? A little? It will only do the following format for the links in the sitemap: <url> <loc>http: // www. my site .com/</loc> </url> <url> <loc>http: // www. my site .com/link1.php</loc> </url> Etc...etc. Would this be sufficient enough do you think? I usually use a manual format more like: <url> <loc>http: // www. my site .com/</loc> <lastmod>2009-12-31T05:32:37+00:00</lastmod> <changefreq>daily</changefreq> <priority>1.00</priority></url> Or this: <url> <loc>http: // www. my site .com/</loc> <changefreq>weekly</changefreq> <priority>1.00</priority> </url> I would love to save myself the time involved and let an auto script do it for me. However, I don't want to end up making search results worse by doing so.
lastmod - useful changefreq - garbage priority - useful, but must be managed I've put together a page regarding XML sitemaps here: thistleinfotech.com/xmlsitemaps.html At the end of the page is some information regarding those tags you mentioned:
Most people use priority values the wrong way. Never ever set all URLs to same value at least, better remove priority values then You might want to read this article about XML sitemap priorities.