Not to argue your other two points, but store-bought razor blades are hideously overpriced — right along with authorized-by-company inkjet cartridges. Harry’s, the first company to sell razor blades on the Internet, charges $16 for eight razor blades, which used to cost me about $40 if I bought them in a Big Box Store, and closer to $50 if I bought them in drugstore/supermarket four-packs. That’s absolutely worth it to me.
For a lot of us, an electric toothbrush is a far more effective way to clean our teeth than a regular toothbrush is, getting all that grucky tartar and bits of food that you miss when you’re brushing your teeth with a regular brush. (Flossing helps, too — or do you also sneer at that as Yuppie Affectation…?) I don’t know how much Juicero charges for toothbrush heads — but given that three toothbrush heads normally cost about $20/pack at the drugstore/supermarket, if they can cut that price at least in half it’ll be worth it to me, same as Harry’s is for razor blades.