Today, Roku ads business is the top player in connected TV. This week, the company announced that it added 1.6 million active accounts in the first quarter of the year, reaching a total of 71.6 million active accounts.

Streaming hours also increased by 4.2 billion year-over-year, reaching a total of 25.1 billion. Overall, Roku’s data shows that 50% of all AVOD impressions occur on its platform.

Although the company’s ad sales business eventually made deals with every major holding company and has a commanding presence in the upfronts, serving most Fortune 500 brands, that growth didn’t come easily. It rarely does.

Founded in 2002 by Anthony Wood, Roku set out to revolutionize streaming before the concept even existed. But to get there, it needed the help of advertising dollars.

Alison Levin was Roku’s first hire in ad sales. She joined the company after already having experience selling connected TV for brands like Samsung and LG at Tremor (now Unruly). Roku contacted Levin for a business development role designed to add inventory and channels, but no sales team existed. After initially declining the offer, Levin joined right before Roku announced its first partnership with Nielsen to bring its Digital Ad Ratings offering onto the platform.

Dan Robbins at Nielsen led the deal, eventually joining Roku himself and becoming its VP of marketing and partner solutions.