Five more advertisers announced they will no longer advertise on Rush Limbaugh's radio show, bringing the total number to 20. But industry insiders say most ad dollars are simply moved around temporarily and sometimes they even come back. "While ad exits make headlines, they don't necessarily account for typical sponsorship cycles," Brian Steinberg wrote in the marketing industry magazine [Ad Age on Monday.]( "Advertisers may appear to leave, but they more often simply move to the sidelines. Sometimes, they even come back."