Factors that affect ad serving
Google doesn't guarantee that we'll always have relevant ads to display, because ad serving depends on a number of factors, including our ability to crawl your site, your webpage content, and the availability of relevant Google ads.
Similarly, if Google does not have ads for an AdSense for search query, or if the query will return non-family-safe ads, we will not show any ads.
If we don't have relevant ads for a given webpage, or if we haven't yet crawled your site, we'll display no ads. Alternatively, you can set the backup ads of your choice to take their place.