I have a few pages on my site(s) that are created dynamically via a CGI script when a user visits. On these pages, however, I generally get no Google ads, or I get shown ads that are totally irrelevant to the page's content. These pages do have textual elements, but they are not standard HTML pages. Is there a way to inject topics or keywords in these pages (via META tags or other hidden means) that would better ensure I'd get relevant Google ads displayed?