There is a misconception on the web that has cost many webmasters and speculators a lot of money.
This is the assumption that the rules that apply to real estate in the brick-and-mortar world, are the same rules that apply on the World Wide Web. This is one of the reasons why many folks can never abandon the idea of acquiring as many domain names as they possibly can. The thinking is that as long as they have a "piece of dirt" online, they can't go wrong the moment they introduce "bricks and mortar" to it.
The first difference that you need to take note of that makes offline real estate very different from the "real estate" online is the simple fact that in the real world land is limited while in cyberspace it is unlimited. This is probably the most important difference. It means that domain names are worthless, if one cannot get some serious traffic flowing in its' direction.
Already this is very visible in the numerous sites that have taken up vast amounts of resources and cash to set up but are worthless because they are unable to generate enough traffic in their direction. Despite all this evidence of the trends online, there are still many site owners who will instinctively purchase dozens of other domain names every time they need a new one. Remember that although domain names are very cheap to acquire, the numbers tend to add up very quickly and after a few years, many people find themselves with huge bundles of domain names that are worthless and will never be used by anybody. The cash that went into purchasing them would have been put to much better use doing something else like paying for ppc (pay-per-click) ads to generate more traffic in the direction of the domains that have been put to use.