Online video ad platform TubeMogul is expanding into Canada, as spending on streams continues its years-long double-digit gains. Still, the space is still held back by a lack of standard measurements. The online video ad dollars being funneled through real-time bidding platforms remains a relative drop in the overall $30 billion dollar U.S. digital ad market. A Forrester report commissioned by TubeMogul says that there will be $687 million in gross sales of online video ads through real-time bidding platforms by 2013, while digital video ads could reach $5.4 billion by 2016, a 250 percent rise from 2011. Until the industry reaches that point, TubeMogul needs to provide as much scale as possible. AdExchanger spoke with CEO Brett…