Recently there was this big discussion if Google Sitemaps is a good thing or worthless extras, but let me share with you the true story.
Sitemaps is one of the best inventions introduced by Google and is now even adopted with Yahoo and you wonâ€˜t be amazed when you see the /sitemaps.xml file being requested by “Yahoo SHLURP” bot. The sitemaps as the name explains it is a well structured map of your site – each individual url and its priority for the website. The priority is very nice to be set up carefully and therefore put larger value (1) to the main page www.domain.com/ and less value on the pages that are not going to change after their creation, because the higher this value is, the highest priority in their list this url will have and will be the first indexed on a deep crawl
On the other hand the Update rate value is really worthless thing because most search engine do not obey it and thatâ€˜s a well known fact. Search engines will visit your url only if they stumble across a link to that page and in most cases they will index only the page that is linked. During the deep crawl (which is done once a month) then the whole page with all the urls will be indexed. Donâ€˜t think that when Google opens your website it will get the whole thing at once .. nope .. the situation is a bit different and Google will index few urls, then make a pause and come back again until the whole website is indexed.
Another important part of the sitemaps is that you have to add it on the Google Webmasters Center and verify your website in order to get the maximum benefits out of it. If youâ€˜re using WordPress or SEO Website CMS they will automatically ping/request Google to get the sitemaps file, but if you are not using those CMSes that has to be done manually – go to the google sitemaps and click UPDATE