Lunchbox Sized Bags: Cost Effective Brand Awareness

Lunchbox sized / small bags (such as by Lululemon) are probably some of the most cost effective brand placement options available today. 

People carry your branded bag on their way to/from office or school. They fill up the office fridge with it. The bags last forever. People seem to never switch once they start using one.

Plus, the company already has to spend money on bags for point of sale.