Online video viewers recall seeing pre-, mid- and post-roll ads more often than any other display ad type, according to a study by Yahoo.

eMarketer said, citing the Yahoo study, that over half (53%) of respondents who recalled seeing some advertising remembered viewing in-stream ads.

Like its static display counterpart, banner ads, online video advertising can appear in numerous ad sizes, placements and creative types, making it difficult for marketers to decide where to start.

However, the pervasiveness of an ad unit type can still have a large influence on recall, said eMarketer. It said 35% of viewers were able to recall seeing static banner ads, while only 13% of viewers remembered seeing seemingly more eye-catching video banner ads.

The study found that pre-roll ads are the most recalled ad unit types.

Break Media said that pre-roll ads are also the most used video units by US marketers.

The study also found that nearly half of the respondents also recall the ads’ subjects after watching an in-stream ad.

It found that 47% of respondents said they remembered the brand or product advertised after viewing a pre-, mid- or post-roll video ad.

Expandable video banners and pop-up video ads to prompt user action, with 39% of respondents reportedly acted after viewing an expandable video ad, compared to only 20% of pre-, mid- and post-roll video ad viewers, found the study.

Expandable and pop-up video ads were also more likely to aid users in purchase decisions than any other display ad type.