During the last few years, there has been a switch between traditional media consumption into online media. Millennials in Indonesia, which is currently the biggest age group on the internet, seem to regard social media like Youtube as their go-to online video platform. This caused marketers to compete with each other in creating the best video advertising to grab their attentions. On the other hand, few researchers have found that millenials are avoiding ads. This has become a problem for marketers, as video ads aim to grab the interest consumers to buy their products, ended up not being able to communicate their messages to the consumers. For this reason, it is important to analyze what kind of factors that will interest the millennials to accept online video advertising and if these factors impacted purchase intention. Survey had been conducted to 400 millenials in Jakarta, and the gathered data will be using exploratory factor analysis and path analysis, respectively, to find out how each factor impacted their attitudes and intention to purchase. The results of this research could help marketers in creating the best online video advertising for millennials by showing that ad entertainment, credibility, and emotional appeal simultaneously have significant impacts on attitudes toward social media advertising and purchase intention.