The correct spark plug and gap is crucial to proper ignition. Spark discharge is a breakdown in the air insulator between the electrode and ground. Yes - air is an insulator, a pretty good one at that. As voltage builds at the electrode, atoms in the air within the air gap gain electrons. This process is called ionization.
It's one of the reasons why our standard lenses are polycarbonate (thinner than standard lenses typically sold by other eyeglasses retailers). At Warby Parker, you can upgrade to high index lenses for an additional $30 whereas it typically costs $60 to $100 more.
(Target's watch battery prices range from about $3.69 to $6.50 at the Lake St. store in Minneapolis.) But at The Watch Shop in St. Louis Park (7724 13th Lane, SLP, 952-542-8685), I was charged only $10 to have three batteries replaced (price included the batteries and labor).