For me, it increase the number of indexed pages, and with it my co-op weight I did not get any more traffic from google. see image, number of indexed pages by google for some website.
thanks, good chart. has anyone ever reported a negative impact on their rank on google because of sitemaps?
Using (or not using) Google Sitemaps in no way influences you site's rank - they say this in several places in the FAQs.
regarding the chart- i think i can safely assume the vertical axis shows number of indexed pages. absolute values are irrelevant, derivative is what is interesting... what is the horizontal axis suppose to show? hours,days,months? thanks in advance. -- vbrocks.net
hehe, sorry Y : indexed pages (as reported by google API) X : days (from left to right, last column being 'today') and the red line indicates when I submitted a sitemap to google sitemaps.