Disable all browser add-ons and browser extensions and I bet that those "ads" will disappear.
WordPress.com does not use text enhance or text link ads or pop-up ads or links in comments. So far everyone who has reported this has had a browser-add-on or browser extension that causes it. In some cases it was embedded into free games they downloaded from the internet. In others it was in toolbars and shopping apps.
Please try logging out, clearing your browser cache and cookies, disabling all browser add-ons and extensions, clearing your browser cache and cookies, and then rebooting and logging in again. View your blog and tell us if you still see advertising or not.