A survey of digital marketers worldwide reveals that many are faced with a variety of video advertising concerns—particularly fraud and the ability to measure their video investment.

The study from growth marketing platform YouAppi, conducted by Dimensional Research, found that 48% of respondents are concerned about fraud on the ad networks that deliver their video, up from 33% who said the same in 2017.

And nearly half (45%) said it's difficult to effectively measure the impact of video investment. By comparison, 40% of respondents felt that way last year.

Interestingly, targeting the right consumer was less of a concern. In 2018, 26% of respondents cited it as a challenge of video advertising, down 5 percentage points from last year.

Challenges aside, more marketers are investing in mobile video marketing this year than they did in 2017. In fact, 84% of respondents said they plan to increase expenditures, up 10 percentage points from a year earlier.

Many marketers also believe video advertising is a channel that's critically important to the customer journey. Indeed, 96% of respondents said video is at least somewhat important.

Video viewers continue to increase year to year, though growth rates are slowing down as the category nears saturation. Some of this growth comes at the expense of traditional TV, which appears to be declining faster than previously expected.

eMarketer estimates the number of US digital video viewers will reach 228.8 million this year. By 2022, that number will increase to 248.9 million.