Contact Forms
Website that has form to fill out, before the user is able to view it are a
waste of the users, and the web developers time. You should only have to fill
out a form if you're buying something, or requesting someone from a company to
contact you! I also hate excessively long forms, especially those that have
fields that aren't required. Why have a form with 30 fields, most of them
unnecessary, and only two or three fields that are needed? Wouldn't it be nicer,
and less intimidating to just have the two or three fields that are required?
The user would love you for it.
Pop-up Windows
Oh how I loathe these. Does anyone like these? Why on earth would you pollute
your website with them?
ADs
Similar to pop-up windows, these are annoyances on the user. Do you really think
you'll get rich by putting advertisements on your website? The only way that
would happen is if you had an incredible amount of traffic on your site.
Broken Links
Be sure to check the links to other websites monthly, to repair or delete broken
links. What good is it to your users if many of your links no longer work? It
just shows them that your site is dated, and unkempt. That gives them a reason
not to return to your webpage.
Continual Reorganization
It's annoying for users to bookmark a page and then find that the bookmark no
longer works, because you moved the page. It's also frustrating when people use
search engines like Yahoo/Google and they find the page you made no longer
exist.
Text That Moves
Scrolling text is an annoyance, with the only exception being stock quotes.
Animated GIFs
These were 'in' during the mid nineties. Now they're distracting at best, and
absolutely hideous when over used.
Flash
If Flash was used in moderation, it would be acceptable. Unfortunately, it's
overused. I've found that most sites with Flash, while graphically beautiful,
have little to no worthwhile content. Flash is best used for making simple web
games, or animated demos to explain a concept.
Difficult reading
When the colors of the text are too similar to the background, it makes reading
difficult. Not everyone's eyesight is as good as yours. It's also difficult to
read a webpage that has a background image behind the text. If you must use a
background image, please have it faded, so the text can be read. Here's an
example.