This is by no means an exhaustive list, but it does cover some of the major offenses committed in web site design. There are many examples on the web that use mistakes like these, while some try to use several of them all in one web site.
If a site takes more than a few seconds to load, visitors will not stick around. Proper optimization of images and code can dramatically increase download speeds.
One thing you don’t want to do is blind your customer/users. Bold, flashing ads fit into this category as well. Blindingly bright colors will bring them a good case of eyestrain. Some should state: “WARNING: Might cause seizures”. Believe me, your visitors will not be able to stick around.
Without proper navigation, your site visitor cannot move about your site to find the product or information you are trying to get them to look at. Navigation should be obvious and in the same spot on every page. Visitors are not going to stick around if they can’t immediately find what they came to see.
We've all encountered these. You’ve begun to look at the content of a site, perhaps an article or product description, and out of nowhere a little box pops up in front of what you are trying to look at. Helpful Hint: Don’t interfere in what your customers/users are trying to look at with something that can easily be inserted statically near the content. If your customers/users want to act on these, they will do so all on their own. If you do insist on using this tactic, at least ensure that the boxes cannot interfere with content.
Making a visitor download some plugin just to make your site work for them is never a good idea. People are skeptical of downloads that they do not initiate on their own…especially ones that are forced on them.
Ask yourself whether you want your visitors to wait several seconds for these to load just so they can get virtually no information about what you do or sell. Also, ask yourself if your money could be better spent on something that does not interfere with your customer’s reason for visiting your site.
You’ll find these little nuggets of information at the bottom of a site telling visitors the site will look better to them in, for example, Internet Explorer 9.0 and using a resolution of 1024x768. In the first place, the site should be viewable in any browser and resolution; otherwise, the web designer needs to be fired. It’s called cross-browser compatibility!
Imagine the search result…“Untitled”. It won’t even much matter whether you put a description in at that point. Do you think potential visitors will choose your “Untitled” page over one that has a descriptive title? Make sure you have titles for all pages and each title is relevant to the content of your pages.
Never make your visitor scroll to the right just to read the end of your sentence. This is the epitome of bad design.
Background images can really set off a site if they are tasteful and clearly go with the design; however, one little techno-colored image tiled to create a background will scream unprofessional to visitors. Worse than that is trying to insert text over these types of backgrounds.