Alan Bleiweiss: If your internal link architecture is set properly, there in no absolute need for a sitemap.
Oliver Max: Right...yet even if no absolute need for a sitemap exists, any professional SEO would set one up as part of the basics wouldn`t they?
Alan Bleiweiss: Oliver no. If it isn`t needed, it isn`t needed. Yes, it can help reinforce URL indexing intent. However it is a second tier discovery source except on complex sites (tens of thousands or hundreds of thousands or millions of pages with complex link flow)
Rob Woods: honestly, I like to have them set up as a diagnostic tool much more than for URL discovery. i.e. if you have a ton of URLs indexed that aren`t in your sitemap, why? They really aren`t needed for ranking unless a site has serious issues that should be fixed anyway. Having said that, yes, I do usually set them up and submit them in most cases.
Vernard Alexis Luz: Good point, Rob Woods.When the no of indexed URL is a lot more than the pages in the sitemap... You know there`s something wrong.
Alan Bleiweiss: Vernard or when you have 25 sitemap XML files with 15, 000 URLs each, where some only have 1, 000 URLs indexed, it can help narrow down problem file or content type patterns.
Oliver Max: mmhhh Maybe I should have phrased that differently. Sorry. I`ll try again - if somebody is lacking a sitemap, is it (90%+) safe to assume they haven`t hired an SEO to do (on-page) SEO for them?...I`m wondering whether when I`m in a niche where none of the first page results have sitemaps, it`s a strong indicator that none of them have done any proper SEO and that the niche is not very competitive...? Thanks brother
Ash Nallawalla: No. In some large companies, the SEO is at the mercy of the developers and other demands on their time. I have worked in places where I was asked, "will this make us more money than (whatever they were also asked to code)?"
Jenny Halasz: How do you know they don`t have a sitemap? Not all webmasters name it sitemap.xml
Ammon Johns: No.A sitemap is a decent aid to page discovery, but, in SEO, if you need the sitemap to do that, you`ve already lost.Now, a sitemap.xml is certainly useful for the google analytics and reporting tools, but there`s a lot of serious SEOs who don`t give all their data to Google, and prefer other solutions for their analytics.Sometimes the lack of a sitemap.xml might mean they aren`t serious about SEO ... and sometimes it means they are much better at it than you. :D
Bonnie Burns: You really don’t need a static sitemap. But there should be an xml sitemap for pages, posts, video
Mike Gracia: You know what they say... Assumption is the mother of all SEO feckups :) Being more serious though, I wouldn`t assume anything from there being no sitemap. Also, remember XML sitemaps can be hosted on a different domain (although you`d usually be able to find it in robots.txt ).