Comparison Shopping Engines - An Introduction

Many people like to shop or surf for products and compare prices, on line. It’s fun and easy. But if you are serious about shopping on line, then there are several issues that you have to deal with. One of the most serious is getting the best information about prices and products to have a meaningful comparison. One way to compare prices is by using a regular search engine. But that can be tedious and time consuming. Instead comparison shopping engines have become popular among online shoppers.

Comparison shopping engines are harder to build than at first look. At this point no one company has been able to create a dominant technology for the comparison shopping market in the same way that the popular Google or Yahoo has managed to rule the web search market.

So what do the shopping engines provide? Usually, they try to address two concerns when a consumer uses a comparison shopping engine. One is for the product - to get the lowest possible price. Secondly they try to find information about products in order to make an informed selection.

This really is harder than it looks. At present, most shopping engines are focused on pricing; how to provide the lowest price and it is hard to include information and reviews because this information is much harder to obtain. But there are companies trying. A few small startup companies are focusing specifically on searching for product information to help consumers choose the right product.

Comparing the Comparison Results

One problem that frequently comes up is that a strict price comparison is not the exact science it might appear to be. If you try searching for the same item on several price comparison engines, you’ll find that the results can vary widely.

So here is what happens. It quickly becomes clear that in order to have any confidence that you are finding the best value, you have to get results from more than one shopping engine. You have to compare the comparison results. So why does this happen? What’s at play here?

Comparison Search Engines are not the Same

There are basically two ways to get information. You crawl online merchant stores to get information. The information is then indexed. So what you must do is build a software program to visit the merchant websites, analyze the HTML pages and find the information and prices for the products they offer.

Crawling doesn’t work for comparison shopping engines; not in this way. The reason is that there is no standard way to represent the product, the price, and description. The information may vary widely from merchant to merchant, even when comparing identical products. Then again merchants may change the format of its website; in this case the crawler may stop working properly. And finally, products and prices change so a crawler must continuously visit the merchant websites in order to insure that information is up to date. So all of these problems impact how information is displayed.

Data Feeds

The difficulties outlined with the crawling technique present an opportunity for the use of a second method: data feeds from the merchant stores. Data feeds are special files prepared by a merchant, which are made available to the shopping engines. The feed data is provided in a nice format which is easy for the shopping engine to understand and analyze. This is faster, easier, and accurate.  But the big disadvantage of the data feed method is that the data must be prepared by the merchant. This can be time consuming and costly. But a more prominent issue involves updates. Data feeds must be kept up to date; and this will depend on the merchant’s willingness to do that. The drawback can be if the product inventory is large, the merchant may not put his entire inventory in the data feeds; just what is popular or the most profitable.

If there is no standard data feed format, one merchant may only stick with one search engine, and not go with multiple ones because it would be too costly to provide multiple data feeds.

Not Always – the Cheapest Items are Displayed First or on Top

You’d think that that would be the most natural way to display information cheapest to most expensive. However, this may not be the case. Different merchants may be willing to pay different amounts to get listed first. In these cases, you will very often find that results from the merchants that are willing to pay the most are listed first, regardless of the price of the product.

How to Work with Multiple Comparison Shopping Engines

Finally we arrive at the real point of all this: You really need to use more than one comparison shopping engine if you are serious about finding the right product and the best price. RoboShopper is a meta-comparison shopping engine. With it you enter your search keyword and then click shop. This will take you to sites which specialize in product information and reviews, as well as online price comparison services.

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