It was already in 1999 when
Lawrence and Giles discovered that just a fraction of the whole WWW was indexed by the search engines. By that time,
HotBot had the highest coverage, with barely a third of all web pages covered. Google migh have improved the situation a bit, but it's bound to get worse.
For starters, it should. For Google to index something, somebody must tell him to do so. A standalone page, not linked by any other, will never be found by google. Web pages change, and Google can't keep up with them. Some pages don't want to be indexed. And some are simply not found, for some other reason.
Some are probably dropped from the database. Search time for Google is bound to increase with the number of pages indexed, and there will be a moment in which all the database can't be searched in
real time (well, in a very small time, anyways). You can add more computers, do stuff in parallel, create specific processors, but that will increase the price of every single search, and it will become economically unfeasible to do so; even more if search becomes more complex, by an improvement of the algorithm, or by additional features. Then, Google (or any other search engine, for that matter), will start to "not find" stuff. It's probably not too bad if it finds enough stuff to make you happy, but it will probably not please the merchant or commercial sites which depend on search engines for plying their wares.
But that's not the only reason. The internet is now almost synonymous with the web.
HTTP Traffic accounts for around half of all Internet traffic. But this percentaje is also bound to decrease; it might be overcome by, who knows, P2P traffic or instant messaging traffic. Even if HTTP prevails, XML might be used more than HTML, and even if does not happen, dynamic web pages will surpass static web pages.
There are so many things that can fail, that my opinion is that searching as a mass business has an expiry date.
The Economist has a nice article along those lines (via
Blogdex). The question is, ¿where will it be in a few years?
