If your pages have lasting value, don't stop after promoting them once.
Pages often disappear from search engines.
If a spider doesn't find your page just once when it tries to revisit, the page is dropped. Revisit the search engines periodically to check your listings. If they have disappeared, put them back. Anytime you update a page with new content, update your meta tags, and resubmit to the search engines again so that they will reflect the new content. The newest listings often get favored in the order they are displayed, other things being equal.