I want to thank Zack Miller for responding to my blog post from last Friday. Miller's big beef with my post was that I argued that Google is really just a search engine -- and one that could be defeated by smaller startups and vertical players. Miller, on the other hand, contends that Google is no longer just a search engine. But is Google really more than just a search engine?First, I'm not convinced that Google's other, nonsearch product offerings are as successful as the company's advocates (including Miller) would like us to believe. As I pointed out earlier today, Google dropped its paid video service. Google has been far from successful in China, where it has lost market share to Baidu, which is the dominant search engine in that market. No one can tell me how successful Google's mobile initiatives are to date, despite all the hype surrounding the Google Phone. Anyone remember Google Answers? I think you see my point.

Sure, Google has enjoyed a lot of success with some nonsearch services, like Gmail. I'm not going to argue that it hasn't. But, I'm trying to demonstrate that Google is vulnerable and that it is far from perfect. To date, Google's biggest successes remain its search engine and the massive ad machine that sits on top of it. Would anyone seriously argue that Google's business would survive if its search engine were to collapse tomorrow? I don't think so.

So Google's biggest strength -- and hence its biggest weakness -- is search. I agree with Miller, Google is pushing hard to maintain its position as the king of search. No doubt Google will spend mercilessly to protect its position. But Google can't possibly buy every little search engine that outperforms Google in some select vertical or niche market, not even with its massive market cap.

I also agree with Miller that it's more convenient to have one company serve as the mediator for the entire Web, but I don't think that's possible over the long run. The Web continues to fragment and as it does so, too, do its services. We've already seen this in the social networking market where sites like Facebook and MySpace are evolving in different ways to serve distinct audiences with unique services. Search, it seems to me, has just as much possibility to fragment, with niche engines responding to specialized audiences with customized algorithms, categories, etc.

Let me also repeat why I think all these little search engines will eventually hurt Google's search market share:

Both Technorati and Blinkx are beating Google because they're focusing on areas too small for Google's attention. You know, just the same way Google beat Yahoo at search by focusing on the part of search -- namely the algorithm -- while Yahoo was focusing on becoming the all-things-to-all-people portal.

It sure looks like history is repeating itself with Google. While Google is tirelessly trying to avoid being one-upped by the market, it looks like some of the Web 2.0 startups out there are finally starting to eat away at Google's business. I have said this before, and I'll repeat it here: It looks like Google could face death by a thousand cuts.

Google's push to be the entire Web could well prove its undoing. This move hurt Microsoft when it tried to turn Internet Explorer into the locus of the Web and it damaged Yahoo when it tried to turn its portal into the cornerstone of the Internet. Let's not forget that when Yahoo took its eye off the search prize, it enabled a little upstart called Google.

What do you think? Am I being too harsh on Google? And will Google win the vertical search market just as handily as it won the first wave of search?