why google adsense is not showing earings of blogggg

<script type="text/javascript"><!--
google_ad_client = "ca-pub-6604752912607938";
/* swellbuzz_main_Blog1_300x250_as */
google_ad_slot = "4646533202";
google_ad_width = 300;
google_ad_height = 250;
//-->
</script>
<script type="text/javascript"
src="//pagead2.googlesyndication.com/pagead/show_ads.js">
</script>