Best SEO practice dictates that duplicate content, the same content found on multiple pages of one domain, is widely frowned upon. Most of the time, duplicate content is unintentional, either due to a lack of knowledge of its destructive consequences or just out of blatant disregard.

That being said, there are times when you do need duplicate content on your website. Consider an ecommerce site, particularly a product catalog, for example.
In a product catalog, it is not uncommon for the same product to be associated with multiple categories. For this very reason you could possibly have the same content on multiple URLS…

http://domain.com/category/product.html * I want this to be indexed.
http://domain.com/category1/product.html
http://domain.com/category2/product.html

… which will all show the product details for one specific product. Now ideally we want search engines to only index one of those pages and ignore the other two. Fortunately, Google, Bing and a few other search engines, allow us to circumvent this problem rather easily by using the canonical link element. The canonical link element, which is put in the HEAD section of an HTML document, tells search engines the preferred location for a particular URL. So in order for the search engines to ignore two of the pages from our example above, and only pay attention to the page we want indexed, the following line can be added to both pages we do not want indexed:

<link rel="canonical" href="http://domain.com/category/product.html"/>

[/source]
Now when the search engines visit the pages with that element, they will only consider its canonical location in their indexes. It should be noted however, that you should still avoid duplicate content at all costs, but there are some times when your application truly needs it, and for this, the canonical link element is perfect.

Do you often make updates to your site and wish you could change the look and feel in the live site without making changes to the site files? Google Chrome provides helpful extensions that when combined, allow you to achieve great changes to the site.

Below are a list of some very useful extensions and how you can use them to perform changes.

IE tab:
This extension is a wonderful addition for developers to cross browser check the look of the site in IE browser without having to installing the actual browser. Chrome will change the current tab being viewed to an IE tab.

Eye Dropper:
The Eye dropper is an extension that allows you to obtain colors in Hex value from the current page being viewed. One of its features provides a history of the colors you have selected from a webpage; this is a great way to be able to reuse the color without having to use the eyedropper twice to know its value. The only restriction faced, was using the eyedropper on Google pages, since you are not allowed to retrieve any color from Google pages due to a Google Chrome policy.

Measure it:
This tool helps you get measurements in pixel width and height that can be very useful when making updates to a website. These changes can include changing the width of the entire website, an image or a container of contents, this being a table or a div.

Awesome Screenshot:
This extension allows you to save a page and perform a crop, add text, lines and circles that help you illustrate the changes you would like the page to have. This can be a very useful tool to communicate between clients & designers as well as developers & designers. The tool also provides a back function to undo any of the additions made to the page. You can then right click and save the image as jpg.

Stylebot:
This is an open source and a very user friendly tool, which allows you to change the styles of a website as well as remove content from the page. It allows the selection of tags and the ability to change their color, font size, location on the page as well as visibility. This is a tool that can come in handy when requested to make quick changes for review before implementing the actual change. 

When combining some of these tools together you can create a great and fast work environment when it comes to making style updates to sites as well and saving a jpeg of the changes with comments on each of the changes. These tools can also help show clients how a few changes can make their site load faster, as well as explain in detail changes that will help the site be more search engine friendly.

ASP.NET is notorious for generating some ugly markup in the HTML it generates. The idea behind search engine readability is to get the relevant content as close to the top of the HTML Source as possible.

One of the biggest culprits in terms of unnecessary code at the top of the page is ASP.NET’s VIEWSTATE. VIEWSTATE is ASP.NET’s way of making it easier for the programmer and end user to remember certain pieces of information about a page as it is being used. It does this via a hidden form field. The best way to minimize the amount of VIEWSTATE text that appears in the HTML source code is to disable it (it’s enabled by default) and only add it when you need it. Another technique for dealing with VIEWSTATE is to move it to the bottom of the HTML source code. A while back I wrote a blog post on how to achieve this:

A technology that ASP.NET employs that “makes things easier for the developer” and offers a rich end-user experience is the AJAX Control Toolkit. The AJAX Control Toolkit lets you quickly implement things such as modal dialogs (e.g., Lightbox), form field enhancements and partial page updates. The problem with using it is that it also adds an enormous amount of code to the HTML output. The best way to minimize this is to use an alternative to the Toolkit such as jQuery or MooTools. None of the code gets auto-generated in these libraries and the end result is usually nice clean HTML source code.

If you follow the above suggestions, you can greatly reduce the amount of unnecessary code in your HTML output. One of the key points to remember is that anything ASP.NET auto-generates, though great for you as a developer, probably isn’t that good for SEO.