It's a very intriguing statement, but I miss the insight to understand why it's true. Sure, you can name lots of businesses that would have had an offline equivalent, but why does it follow that you're in trouble without such?

Making a rule of thumb from partial data gives you a blind spot;example of non-conversions some mentioned github, lighthouse, basecamp. Fact that software is eating real businesses - does not make a market to be.

I would say be open to all ideas and try them in a short run. Coding never been easier. Launch in couple of weeks and look at the response - any kind of coherent idea you might get.

my 2c

What's the offline equivalent of Dropbox? Klout? Bottlenose? GitHub?

Having people used to a certain concept and then migrating that concept to the web contributes a lot to the success of a product. It saves you the trouble of introducing abstract concepts to the average user, which could be sometimes troublesome.

However the generalization of this observation is incorrect, it is inaccurate and should not be used as a rule to define a good product and\or startup.

Guesses (and probably not good ones)

Dropbox: P.O. Box? You can send almost anything to it but only X people have access (whoever has a key)

GitHub: Science Publication? Where everything is typically based off prior research and people can choose to "Fork" previous research to publish a new concept

Klout: Diner's Club Card? Masons/Lyons clubs?

Bottlenose: TV Guide?

Just taking stabs... it is an interesting question but I agree I'm not sure what the benefits are for being able to relate directly to an "offline" concept.

I suppose one benefit is if you really can say "We are like TV Guide for the Internet" then you can use that to help you make decisions (what did TV Guide do right and wrong).

Offline equivalent of Dropbox is a usb key you carry around with you everywhere you go.

Except you can't use the USB key in two places at once.

The offline equivalent is just how people achieved something similar beforehand. It's ok for it to be worse. I think the USB key is just right for Dropbox's offline equivalent.

You can't be in two places at once. ;)

Or a medieval strongbox?

More important is the question, "Does it fulfill an offline need?"

Will it make me more money? Will it make me more friends? Will it bring me love? success? food? shelter? Will it save me time?

What kind of needs are there besides "offline" ones?