Sitemap.xml: how important changefreq tag is

Every time I build a sitemap.xml I stop at the <changefreq> tag.

How important is this tag?

Imagine a post, once written ain't gonna change, so what value should changfreq acquire?

Witch are the drawbacks of not setting up the changefreq tag.

How important is this tag for google in your opinion?

This value indicates how frequently the content at a particular URL is likely to change.

Even if u leave it blank, crawler can detect the changes schedule..

Use the value "never" for any archived posts that won't change.

It's not an overly important tag and you can leave it out altogether without a problem. Google will soon recognise of its own accord which pages on your site change regularly and which don't.

Of more importance is the last modified tag - this will help Google come by and check any pages that have changed that much sooner than relying on its natural crawl pattern, especially if it's a page deep within your site.

Yeah I was told to change the priority from the default 0.5 to 1.0

Not sure how much this helps though?

Im no expert but I think the tag is probably irrelevant.

Google will work out how often your pages change and if the content is worth returning regularly to look at.

That's based truly on opinion and I await the voice of an expert

<changefreq>monthly</changefreq>
Is nothing but indicating the Google robot how often the web pages is change…This say robot particular pages is modified or change… in week or month etc…..; Actually the Google crawling process is automated… Google bots crawls in its own way or schedule…. What never you display in <changefreq> tag it is not going to affect the crawling process…. If you used this specific tag or not the Google bots will find out is the particular pages in modified or not….

should we make the changefreq as daily? Even if the i've kept that daily, Google crawls only after 4-5 days time.

Forget the change frequency, use the sitemap for its basic purpose..!

I dont think its good idea to ignore "Change Frequency" on google sitemap. There must be a purpose if its showing in google sitemap, dont you think?

Google cralwers are smart enuff to detect the changes on the page, irrespective of the "change frequency" values.. If its a enws site, they program themselves as such to visit more often. If its a general site with less contentchanges happening, the scheduling is done accordingly.. Hence its not important as it seems to be..

But then just to satisfy your thoughts u can always use it..

I don't have <lastmod> on my sitemap and all <changefreq> are daily.
I have a job that creates the sitemap once a day according to the products I have in the database.
Google follows my sitemap exactly as I expect it to do.
I think that they ignore these tags and really look only at the <loc>