Cross Browser Compatibility
If you have every used different browsers and visited the same page with them, you will know that the some pages look totally different. I have done searches at work for items in the past with one browser and clicked on a page that was of interest from the search. When I returned home later that day, I went to the same website using my personal computer running on a different browser and the website looked nothing like it did with the work computer using its web browser.
It’s a sad fact that browsers interpret code differently, but that doesn’t change things. Just because you see your site one way doesn’t mean everyone does, and if your navigation is broken or your CSS has text all over the place in one browser or another, you’re limiting your audience drastically and creating a bad name for yourself. Take the time to test the look and functionality of your site across all browsers
Sense of “Place”
Many times, especially with large, multilayer, thousand page sites, the user looses track of where they are and how to get back to something else they were looking at. This problem is not limited to huge sites though, it occurs on the smallest of blogs as well. There are many ways to create a sense of “place” for your user. In my opinion, the most overlooked tool is breadcrumbs.
Breadcrumbs (horizontal navigation links) are a great, noninvasive way to give customers a sense of place when they’re 8 levels deep on a specific product page or feature list. Breadcrumbs don’t clutter a page up, they don’t eat up a lot of real estate and they provide the added bonus of more anchor text rich links to other pages on your site (if you use them the right way.
Cited: Christina Keffer