So does a properly constructed menu system. Spiders only periodically crawl the XML sitemaps, just like they only periodically crawl the robots.txt file. They should be able to find new pages in your site every time they visit the site through the menu system.
Originally Posted by stuartmike4
Once again, the purpose for an XML sitemap is to help spiders find obscure pages that have become buried over time. It is not intended to help spiders find new pages. Read the Google article about XML sitemaps.
Many spiders will only crawl pages within 3 or 4 clicks from the home page. That is how pages get lost over time. The XML sitemap keeps those pages visible to spiders. That is why it doesn't do anything for a small site.
"It's inexcusable for scientists to torture animals; let them make their experiments on journalists and politicians." -Henrik Ibsen