If a questionnaire is designed to be lengthy (longer than 20mins) it is unlikely to get a high response rate. Even active respondents may feel bored and tired answering questions. Effectively the lengthy survey needs to be divided into a series of separate surveys.

Available response options are hidden until a respondent choose one answer per row. This takes less room on the screen and a faster download time. It is more feasible and less intimidating for a respondent to provide side-by-side ratings of an attribute's importance and ultimately reduce respondent fatigue.

To ensure that respondents watch Ad footage in a given time.
If a respondent tries to skip the Ad, an alert message that they should watch till the end of the Ad and the page does not move on to the next unless they finish watching it.