What's the meaning of these messages littering my Bing WMT message box? I have them for every site I own. Why would they want me to submit URLs manually if I have submitted sitemap.xml file that always contains all the valid content URLs.
Is this some kind of an indication by Bing that sitemap.xml may not be the most reliable way to have them identify new pages? The sitemap.xml files all seem to have relatively fresh "Last Crawl" dates.
So, in general, does anyone actually manually submit new pages to Bing individually?