iabtechlab http://example.com/error http://example.com/track/impression iabtechlab video ad IAB Sample Company 8465 http://example.com/tracking/start http://example.com/tracking/firstQuartile http://example.com/tracking/midpoint http://example.com/tracking/thirdQuartile http://example.com/tracking/complete http://example.com/tracking/progress-10 00:00:16