According to research firm Omdia, online video ad spending is expected to grow at an annualized rate of 14% over the next five years to reach $362 billion in 2027, which puts Roku in front of a big addressable market. Roku: The most popular streaming platform Many brands have cut their ad budgets as discretionary consumer spending has softened in response to high inflation. That trend led to disappointing third-quarter results for Roku (NASDAQ: ROKU).