I know a couple of people who when they used Sitemap the opposite effect happened in terms of there pages were no longer indexed, only the index page was and the pages they put in the sitemap weren't, Google seemed to drop the pages for some reason or dropped like a rock in the SERPS. He said this 'I would loggin into google sitemaps and see that my sitemaps got checked frequently, so I'm thinking google had the sitemaps and googlebot tied together some how(just my opinion).' And the other person said 'could be that google was seeing it as over agressiveness/spam because of the number of updates to the sitemap. just a theory.' Wondering if that is correct? If Google sitemap visits the site anyway would having a sitemap be considered spammy? Why would what happened to them happen to them? Thanks
I have had my sitemaps updated daily for the last 6 months with a PR5 and all of my pages indexed. I run a sitemap service where several others have had daily sitemap updates for the last 6 months as well with no ill-effects so I don't think that my websites are the exception. I'm not sure why they lost pages in the index, but I doubt that it was over-aggressive sitemaps.