The phones--there are two models--produce more than one million minutes of Skype calls a day, Durchslag says.

FORBES: Mobile

There are two models to choose from, the M9 for smaller TVs, and the M12 for the bigger set in your front room.

ENGADGET

There are two models for improving the healthfulness of food products.

FORBES: To Anti-Sugar Zealots, Nothing Short Of A Coca-Cola Ban Is Enough

There are two models to choose from.

ECONOMIST: Devolution

Presently, there are two models in the works, a "combat variant" that just includes exoskeleton legs and attaches at the waist, much like Lockheed Martin's HULC, and the full-body "logistics variant" for lifting crates, missiles, bombs... you know, the usual.

ENGADGET: Raytheon's Sarcos XOS 2 military exoskeleton just does the heavy lifting -- for now

There are two different models, one with headphones that fit over the ears and another that uses ear buds that fit inside the ears.

FORBES: Mixing Music And Mobile Phones

Also, this category has grown in two ways: there are more models, and the cars that are selling well (discounting BMW's 3 series, which always sells well) are larger than they were back in 1998.

FORBES: Test Drives

As Gans says, if the two companies are following very different business models then there may well be room for both of them in the market.

FORBES: Amazon Isn't Competing With Apple: But Their Business Models Are

There are currently two pistol-shaped Tasers approved for use by the Home Office - the X26 and M26 models.

BBC: Q&A: Tasers