XML Data Feeds and Web Services for Affiliates by Carsten
XML DATA FEEDS AND WEB SERVICES FOR AFFILIATES
Article by Carsten Cumbrowski, June, 18 2006 and September 9, 2006.
This is an updated version of my original Scrap. Carsten, 9/9/2006
TABLE OF CONTENTS
Introduction
1. Web Services Basics and Some Technical Stuff
2. Web Services Development
3. Application and Use of Web Services
4. Old-fashioned Data feeds
5. Sources of Background Information and Resources
XML (such as RSS) data feeds and web services are the new buzzwords in affiliate marketing. Let me try
to explain to the non-technical folks what all of this is, what it's good for, and what it is not good for -
and why.
1. WEB SERVICES BASICS AND SOME TECHNICAL STUFF
To get a general idea about what \"web services\" are, take a look at this PDF. The guys from Apache did a
good job explaining it in a short and simple manner.
Web services are based on XML (eXtensible Markup Language), SOAP (Simple Object Access Protocol)
and WSDL (Web Services Description Language). The latter two were developed in a joint effort by Sun,
Oracle, HP, Microsoft, and IBM.
Web services are \"next generation.\" The general technology has been around for a while, but it's now
maturing (similar to AJAX). Things come together and fall into the right place to really exploit the
technology's advantages in an easy-to-use and reliable environment.
2. WEB SERVICES DEVELOPMENT
Visit CJ's (Commission Junction Affiliate Network) webservices.cj.com for their new Web Service
including Documentations and Sample Source Codes. Also CJ's old \"Getting started Guide\" for the Web
Services beta includes references and resources for PHP/Linux developers. Here is a link to an excerpt
from a Wrox book about open source web services using NuSOAP and PHP (PDF ). You can also just
search for \"NuSOAP PHP WSDL\" at your favorite search engine to get a good list of sites about it.
On the latest Microsoft platform, it is even easier. Web services are fully integrated into the current
version of the .NET Framework 2.0. The MS Visual Studio 2005 Development Environment (ASP.NET,
VB.NET, C#.NET, etc.), which is used by Windows developers, makes it really easy to work with web
services.
The new MS SQL Server 2005 also has built-in web service support to allow: easy publication of data via
web service; receipt of data; or going the whole nine yards with interactive and bidirectional
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XML Data Feeds and Web Services for Affiliates by Carsten
communication - for an API, for example. Microsoft released its new software mentioned above at the
end of last year.
If you use older technology like MS SQL Server 2000, VB6, older .NET Frameworks, etc., you need to
install and use the SOAP Toolkit for Windows, which you can download here.
XML data are today mainly processed pretty \"raw\" via applications using tools that are based on the
DOM Object Model. Today, the necessary components are included with operating systems and/or
browsers so as to be a non-issue when it comes to widespread application. The whole RSS, ATOM, BLOG,
AJAX usage is based on that.
Developers need to \"mess around\" way too much with the basics (raw XML) using that technology.
Because XML allows you to do a lot of things and can become quite complicated, many things can go
wrong during the send-and-receive process on either end. That's why RSS and ATOM Standards have
been established. Those are, in essence, nothing more than XML files that have a very specific definition
of structure. It's not flexible, though, and such inflexibility makes it hard to overcome problems.
A good example is product data feeds. The information in a (generally useful) product feed goes beyond
the definitions of RSS (2.0). Google Base was working around the problem by \"extending\" RSS and thus
created a proprietary format, and we are back to square one. Web services using SOAP (Simple Object
Access Protocol) and WSDL (Web Services Description Language) solve that problem.
3. APPLICATION AND USE OF WEB SERVICES
At this time, there is not really any \"generic\" plug-and-play tools for affiliate marketing available using
web services, but that will change quickly, as web services are more and more commonly used.
Web services will not make old-fashioned data feeds in the form of delimited (and maybe zipped) files
obsolete.
If you have a lot of products and the affiliate requires having all the products in its database for special
processing, a web service is probably not such a good idea. However, the question is, \"Do I need all the
product data in my database for what I am doing with the data?\" That's a question that can be answered
\"No\" in most cases.
If I just want to have a little storefront or need the list of all your \"widgets,'\" collectibles, or your price
for a specific UPC for price comparison, I don't have to have all of the data in my database. If I can make
a request, in real time, to your site/servers and get the data I need, when I need it, the process will work
fine. It's even better if I can get the information directly and in real time, because it is up to date. You
can tell me availability, the current price (no more outdated prices on my site), etc.
You see where this is going and I believe that you are going to like it!
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XML Data Feeds and Web Services for Affiliates by Carsten
4. OLD-FASHIONED DATA FEEDS
When it comes to \"old-fashioned\" file feeds, I prefer to work with delimited files. There are fewer errors
possible, the file is smaller, and most \"classic\" applications and tools (Excel, MS SQL Server 2000, etc.)
can work with it. XML files make sense only if you use the data to specify variations of the same product
- variations that are virtually the same with only minor differences, such as different sizes and colors for
clothes.
It is a bit tricky with delimited (two-dimensional) feeds to handle those differences.
Option 1: Use delimited data within a single record (using a different delimiter than for the general feed)
e.g., the \"Tab\" delimited data feed has a column \"colors\" which contains a comma delimited list of all
available colors for the product. That gets complicated when you have combinations of properties like
size and color when not all combinations are available, or when other things change for certain
combinations - like price or shipping cost.
Option 2: For every unique variation of the product, send a complete product record in the feed. The
disadvantage here is that it looks horrible on the affiliate site if there are no means provided to \"group\"
the variations under a \"master\" SKU and avoid the seemingly duplicate items in the product listings. See
a practical example.
XML feeds can also have more data for a simple record. The limitations for delimited files vary from
platform to platform, but I think that in our business it does not really matter. I have not seen a product
feed with too much product information. It is usually the other way around. I recommend taking a look
at my article Merchant Product Data feeds for Affiliates 101 to learn more about data feeds. I also
suggest that you visit my Affiliate Data feeds and Web Services Resources Page.
There are places where you are better off with XML, but honestly, I have not seen a merchant who:
A) generates XML data feeds because of that reason; and
b) does it properly.
I believe (but can't prove) that most merchants today are providing XML feeds mainly so they can say
that they have an XML feed (that is, using a buzzword, being trendy, modern, touting the latest
technology).
FORGET ABOUT CSV WHEN IT COMES TO DATA FEEDS
I am searching for the person who can show me the benefits of a two-dimensional (Excel Sheet Style)
FILE based product data feed over a delimited one.
I agree that \"comma delimited\" is probably not the best choice for a product data feed, but that is
because of the nature of the data in the feed. A comma in the product description can blow your whole
feed if not treated properly on your side and mine.
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XML Data Feeds and Web Services for Affiliates by Carsten
That's the reason I believe TAB or PIPE (|) delimited feeds are the best solution. \"TAB\" is a character
which has no use on the web anyway (there is no TAB in HTML) and PIPE is a character which I have not
seen yet as valid character in product content.
5. SOURCES OF BACKGROUND INFORMATION AND RESOURCES
Sources of Background Information
XML Specification at W3C - XML stands for eXtensible Markup Language
DOM Specifications at W3C - DOM stand for Document Object Model
SOAP Specifications at W3C - SOAP stands for Simple Object Access Protocol
WSDL 1.1 Specifications at W3C - WSDL stands for Web Services Description Language
AJAX stands for Asynchronous JavaScript and XML and is nothing new; it was previously known as
\"remote scripting.\" Microsoft's Remote Scripting (or MSRS) was introduced in 1998. The term 'Ajax' was
coined on 2/18/2005 by Jesse James Garrett from Adaptive Path.
To make it easy to find public web services, IBM, Microsoft, and Ariba started the Universal Description,
Discovery and Integration (UDDI) project. See details at the project's official website.
The passport authentication system is one of the web services in Microsoft's .NET initiative, and is
available without charge at the moment, so developers can use passport authentication within their
own sites.
RSS-Extensions from Google (used for Google Base, for example), Microsoft and Buy.com
Microsoft's Simple Sharing Extensions for RSS and OPML
Google Data APIs Protocol (GData)
Buy.com RSS 2.0 Product Module Definition Version 1.0
Also interesting: Web Services article at AListApart.com.
Additional Information and Resources
APIs and Web Services Resources - Website Development, APIs and Web Services Resources, Tools and
Articles
XML For Everyone - SQL Server Standard Magazine (e-Magazine and Print), 09/2006 Issue
Webservices.XML.com - Articles and News dedicated exclusively to Web Services.
\"Web services\" at XML.com - Keyword Search Results Listing
Reminder: Make sure to check out my popular article about Data feeds for Affiliates 101 and my Affiliate
Data feeds and Web Services Resources Page as well.
Carsten Cumbrowski
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