Why MVT campaign send to 100% of the audience, instead of the smaller sample size?
If this is the first time you have setup an MVT in program, do take note of the following explanation, as a lot of time the test outcome does not seems to be expected (i.e. : the MVT campaign send to 100% of the audience, instead of the smaller sample size).
The MVT campaign is supposed to be “activated” only from the time we want it to start.
For example, if we set to start the MVT test at 5:00am for a duration of 2 hours, it will activate the MVT settings against those enactments that pass through it between 5:00am and 7:00am only.
Any enactments that pass thru the MVT campaign outside this period between 5am to 7am on Oct 21 will not be treated for MVT testing candidate. Rather, it will just be treated for the default campaign settings.
This could explain why your tests show the MVT campaign went out to 100% of the audience, instead of a smaller sample size (i.e.: 20%). Reason being, the enactments had entered the program before the MVT was started. For example, the enactment has already entered (and exited) the program at 4:45am, but the MVT was set to start 15 min later (i.e.: 5:00am) for a duration of 2 hours.
As there is no holding prior to entering the MVT campaign, those enactments that came into the program at 4:45am would have passed thru the MVT campaign that is still no yet activated (for MVT).
So, the easiest way to “fix” this, is to set to “Start on publish” option in the MVT campaign. That would allow the MVT settings to be activated for a duration of 2 hours, beginning from the start of the program being published.
Otherwise, the other way is to put a holding timer before the MVT campaign, so that you would release the enactments into the MVT campaign after the latter has started.