1. If Metcalfe's law can apply for your product, make it insanely cheap and easy-to-use.
2. Assume Metcalfe's law will apply.
Note: The accurate versions of these laws tend to become too long and boring (I think Randall Munroe once did a cartoon on this), so please try to think up the accurate versions and then discard them... :).
Anyway, these words of wisdom originated when I was reading an article about Apple's Macintosh. The Mac seems to be a wonderful piece of work... And everyone who own's one seems to be very proud of it. But, to this day, I personally don't know anyone who owns one, or would even consider buying one.
Why is it so?
I think the above 2 laws are the answer.. PCs were cheap from the beginning. Macs were not (or at least they were perceived to be costly). So, the ordinary Joe went for a PC, and only the elite thought of the Mac. This became a sort of a rule, and the owners of the Mac actually seem to be proud of this. However, this is not good news for Apple - they lose potential customers. So, the folks at Apple seem to be trying to catch up, but I don't think they'll be terribly successful because, whatever Apple does to make Mac better,
* when geek George goes out to buy a computer, he knows that he needs a PC because every one of his friends has a PC, and he would anyway be developing applications for a PC only - that's where the market lies.
* when papa Peter goes out to buy a computer, he knows that he needs a PC - he doesn't want to be the 'odd one out', nor is he delighted by the idea of always having to make sure whether a particular software will run on a Mac before downloading it.
* when grandma Ginny goes out to buy a computer, she knows that she needs a PC - because everyone says so.
So, that quite sums it up - it all comes down to Metcalfe's law. More people use it, more people buy it, more people use it, more people buy it, and so on ad infinitum.
And that perhaps explains the ubiquity of products which are cheap, low in quality, and insanely popular. Just look around yourself, and you'll probably find one...