> "I'd also venture to guess that he appears in a lot of them to cut the costs of the video."

I'm nearly 100% positive is it intentional that Adam stars in most of the videos, and it not due to cutting costs. It is calculated marketing and probably a requirement by Sandwich. Their clients: Ebay, Groupon, AirBnb, Square, Coin, Warby Parker, Jawbone, and Lyft can afford to pay for an actor or actress.