Will the same clip that impacts someone watching a television screen influence a laptop viewer? What about smartphone video viewers? The Online Media, Marketing and Advertising conference panel on “Video on Second and Third Screens” led by Forrester analyst Mike Glantz, offered a number of insights for marketers on how to effectively reach web video viewers.

1. Outline platform-appropriate metrics and create accordingly

The insiders reminded marketers that not all videos are equal, and the screens consumers watch them likely influence engagement. Mobile video ads have the highest click-through rates (as confirmed by Vindico research, which claims mobile ads have 4.15 percent click rates). Panelists said television ads have higher completion rates. (Notably, a study from Adobe suggests mobile video ads still have high completion rates  at 94 percent.) With this in mind, marketers  should think about the length of video spots on different devices and whether the call-to-action comes at the end of the clip (fine for TV) or appears in the middle (perhaps more likely to be seen on the web).

2. Click-to-play is greater than autoplay for web video

One simple but significant insight from Natalie Bokenham of IPG is that autoplay ads boast some of the highest reach rates among her clients, but click-to-play ads similarly drive brand exposure and have better long-term effects. Autoplay ad-driven brand awareness often comes at the cost of perception; she found likability was sacrificed in this format, while click-to-play ads generally foster more positive brand engagement.

3. For mobile viewers, keep it short and sweet

All the experts said the web demands 30-second clips, and even shorter spots are being tested. Indeed, Vindico reports that video ads 15 seconds (and under) have 78 percent completion rates, but this drops to 74 percent completion for videos between 16 and 30 seconds and 61 percent for videos longer than 30 seconds.

4. Keep the focus on goal-driven creative

A lot of marketers may be tempted to use video as an effort to go viral or get flashy. While it’s smart to use this channel to produce high-impact content, it should be consistent with other brand messaging. “Just because it’s video, doesn’t mean that it’s right for your strategy. No matter the format, the creative has to match the goals,” said Christian Waitzinger of SapientNitro. Similarly, Brafton has reported that 70 percent of consumers ignore poorly targeted videos.

5. Use video as one component of high-quality content marketing

The experts emphasized that companies must make sure their sites (mobile or otherwise) have great visual and written content to support video.”Site quality counts! The content around which your web video is placed proves huge in driving positive web metrics,” said Bokenham.

These tips should come in handy for a rising number of marketers, as Brafton has reported that diverse content formats  – including video – are becoming mainstream. Both SEOmoz and IDG report that more than one-third of survey respondents currently use video marketing. Moreover, demand for video content online is at an all-time high. ComScore’s latest figures show more than 188 million Americans watch web videos in a given month.