Mobile ads do work for products that have a practical and important use, like a lawn mower or a washing machine.
Mobile ads do work for high-involvement products (a lot of time, thought and energy is placed into the decision, like a family car).
Mobile ads don't work for just-for-pleasure items, like fancy watches.
Mobile items don't work for low-involvement purchases like movie tickets or toothbrush (ones that pose a low risk to the buyer)