Benefit 1: The “magic zero” effect
The most common point of confusion for a respondent is understanding which side of the scale is positive and which is negative. People often laugh when I say this, but it’s true. For example, a respondent could transpose the values on a 1-to-10 scale to assume 1 is high and 10 is low. (In fact, when we’ve used this scale in the past, we found around 5% of respondents transposed the values. If you don’t have a chance to follow up with the respondent via phone, it could really throw off your results.)
Enter the magic zero. Because zero is intuitively understood as a low or undesirable rating, including it in your scale somewhat “magically” clears up confusion about the high and low of the scale.