Custom search engine
Many e-commerce websites implement their own search engine. Many do it wrong, so wrong that they lose potential customers they won't lose if they had no search engine at all.
Why a custom search engine?
Google provides an easy to implement way to search for stuff within Google on your website, from your website. Ken Rockwell site is an excellent example of such implementation. The website contains a text field and a search button. When entering search terms and pressing the button, the user remains on the website and sees the search results, but those search results are actually populated by Google.
So why creating a custom engine when Google Search can be added within minutes to a website?
Most website owners believe that Google-powered search looks cheap, while a custom search looks professional.
To be frank, many custom search engines look cheap. This is not just my humble opinion: the assertion is based on the rules of interaction design and graphical design which makes them feel cheap. As a developer, I know that behind the scenes, a few PHP coders spent sleepless nights and wasted thousands of dollars of their company or their customers to develop those features, but sorry, the smell of cheapness is still there.
In the same way, Google-based search doesn't necessarily feel unprofessional. It fulfills the business need consisting of letting customers to search for stuff, and it fulfills it very well. That's as simple as that.
How to make a search engine a failure?
Many custom search engines are simply brain damaged. I don't know why they were done in the first place, nor for whom. I don't know how programmers were testing the search engine (obviously, they weren't), and I don't know why their boss or customer didn't care less to do a basic search and see what is actually returned. In all cases, I'm surprised to see how bad some of them are. It's like asking a fishmonger for salmon, and he will suggest you a book about a town in Lemhi County, Idaho, give you a salmon-colored box of candies and talk about the weather for tomorrow. Why the weather? I don't want to know the weather, I just want a piece of fish. Why are you talking about Salmon, Idaho, and why are you giving me candies? You're a fishmonger, not a librarian!
This illustration is not an exaggeration. Many custom search engines behave exactly the same way. They could give you a straightforward answer, but instead, they flood the page with some completely unrelated stuff, show you the weather, and tell that they've found a few hundred results, just not the good one.
How to lose potential customers?
Let's compare Ken Rockwell's website with the website of Phox, a major reseller of photo gear in France.
For this, we will search for “Nikkor 35mm”. If you're not familiar with photography, here's an explanation. Nikon, a large company producing, among others, DSLRs, have a brand of lenses, called Nikkor. As for the “35mm”, non-zoom lenses have a focal length specified in milimeters. So by searching for “Nikkor 35mm”, I want to find the lenses made by Nikon with a fixed focal length of 35mm. There are several Nikkor 35mm lenses, but imagine I'm specifically searching for the one which is small and have “1.8” in its name.
Ken Rockwell's search gives “about 908 results”. The first search page is filled with results containing the photos of lenses. This is excellent, since I quickly see that the second and the third results are not for me: those are the big, professional lenses. The first looks promising, but it's an f/2.8 lens; the fourth result is an f/1.8 lens: that's what I was searching for.
The user experience is outstanding. I type what I need, I click on “Search” button, and voila, a few seconds later I'm on the page I was searching for. If this is unprofessional, I don't know what is.
Let's search now for the same lens on Phox. Great, 0 results. Seriously, one of the largest resellers of photo gear in the country doesn't have any Nikkor 35mm lens? I pick the second most popular brand and one of the most popular lenses, and you tell me that you have nothing? Why spending time developing such useless search feature?
Aside the fact that I've lost my time using the search (while obviously, it is completely unable to find even the most popular product), it also sends a very bad message. A person who is quickly searching for the same lens on different websites to find the best deal would probably think that Phox doesn't have this lens, and go elsewhere.
Moreover, search (when implemented correctly) is usually the fastest way to get to a specific product. Going through the site manually is too slow. For example, on Phox, this means positioning the cursor over “Lenses”, waiting for the panel to appear, moving the mouse to “Nikon and compatibles” (given that the panel is retarded, since it will attempt to close if you move your cursor outside, so those first steps can be a real challenge for many people), avoid clicking on another item with “Nikon” in it, click and arrive to the page displaying lenses which has nothing to do with Nikkor lenses (see that fishmonger who was trying to sell candies to someone who wanted to buy fish?), scroll to the bottom (because the actual Nikkor lenses are outside the visible area), eventually come back to the top, check “Nikon” in “Company” list, wait for the page to refresh, scroll to the bottom, check “More than 29” for “Minimum focal” criteria, scroll again and find five results, Nikkor 35mm missing. Ok, the trick is to uncheck “More than 29” (I always thought 35 was superior to 29, but I suspect now that my math teachers were lying to me, and things are not that simple; maybe in some universes, 35 is actually inferior to 29), to press Ctrl+F, to type “35” and to discover that there is something they call “NIKON - AF-S 35/1.8 G DX”. The name has nothing to do with the official name of the lens (the official name is “AF-S DX NIKKOR 35mm f/1.8G”), and shows that the guys from Phox have a complete misunderstanding of the gear-related stuff, but, well, we still achieved to find what we needed, and we are grateful for them for not finding even more clever tricks to hide their products from potential customers.
Conclusion
When you have to implement search on your website (and chances are, you do), think twice before making a choice.
You can do as Ken Rockwell: provide what your customers actually need, and create an outstanding user experience by helping people to find what they need, and find it fast.
Or you can chose to be corporate, as Phox, with its turnover of 40 000 000 €: spend thousands of dollars to implement useless search which wastes your visitors' time, and spend a few more thousands of dollars to make it tricky to find even the most popular lens while at the same time showing how unknowledgeable you are about the stuff you sell.
The world is not so bad
Note that some companies achieve to create great search engines. DigitalRev is one of them. When typing “nikkor 35mm”, the results are populated immediately. The lens I'm searching for is the first result. A simple click, and I'm there. Great job.