NEW YORK (TheStreet) -- The eyeballs are there, but the marketers have yet to follow.
Mobile devices accounted for 42% of all online viewing in the first quarter, and that figure is likely to surpass 50% by the end of the year, according to Ooyala, a video analytics firm that counts Comcast's (CMCSA) NBC/Universal, Disney's (DIS) ESPN and Univision among its clients.
Yet even as mobile viewing overtakes desktop and personal computers, marketers are balking at spending more of their advertising budget on mobile, said Sorosh Tavakoli, who oversees Santa Clara, Calif.-based Ooyala's advertising technology business.
"While there's a ton of growth in mobile viewing, the monetization is still lagging," he said. "Mobile is behind PC and laptop; it's just not as sold out."
Mobile's ascendancy has relegated the tablet to a niche device.
Viewing on mobile is four times larger than tablet, according to the Ooyala study.
Yet taken together, mobile and tablet viewing increased 100% in the first quarter from a year earlier and 367% over the past two years, according to Ooyala.
Yet, marketers remain wary. Some of the barriers are technical, Tavakoli said, explaining that major brands aren't always satisfied with how a video package plays on a mobile device compared to desktop.
Some of it is historical, said Warren Zenna, managing director of Mobext, the mobile arm of Havas Media.
Large brands have been buying online advertising on desktops and PCs for as long as 20 years, and there is an institutional resistance to getting them to shift their spending habits.