The following are ten most useless features that customers usually request when having their site built. Starting from No. 10...
No. 10: A Forum/Discussion Board
A forum may not be a bad idea if your company has a lot to communicate with your customers -- and when you have a good moderator. A site with an ill-moderated forum looks worse than one without any forum. A ill-moderated (or unmoderated) forum can be filled with spam and scare off your visitors. Real useful posts may be ignored because of the vast amount of spam posts.
No. 9: Background Music
Usually we really persuade people not to put on background music. If you insist to add some atmosphere to your site, at least put some music that suites the style of the site, or put some music that your client/reader might enjoy, and not something YOU like. Just a notice: if your visitor don't like the music, they may just turn away and block your site from search result, so do it at your own risk if you insist on adding music.
No. 8: Flash Animation
Flash does make a site look cool and flashy. But it makes search engine not able to read its contents. Additionally, it doesn't work on Apple products like iPhone or iPad. Our recommendation would be to use HTML5 instead.
No. 7: Disable Copy
If you mind people taking your images or text from your site, you can add watermarks to the images. But disabling copy is not really useful. You can find hundreds of plug-in or add-ons to diable the disable copy function. I can even press F12 to open up the developer's tool to copy your content if I really want to do so. So no need to spend your time doing that.
No. 6: My site doesn't work in IE6
Well... even Microsoft® is thinking about throwing it away. You might as well do that too. Less than 10% of the world is using IE6 now.
No. 5: I want my customers to register
For what? Sending news letters? We are using another service to do our e-mail marketing, you don't need to have your users to register on the site to do that.
No. 4: I need a news page
Unless your company has a lot to blog about or news to share, e.g. Tourism industries, maybe you don't need a news page. Many sites have only one news -- that their site is up -- which is OBVIOUS when vistors are visiting your site. Also, if you don't update your news page, visitors will wonder if the site is even properly maintained.
No. 3: I want to change the design/layout myself
Ask yourself first, "Do I know anything about HTML/Photoshop?" or "Do I even know what HTML/Photoshop is?" If the answer to any of these questions is "NO", then leave the work to the professionals.
No. 2: I want a visitor counter
When your site is just finished, how many people do you think will actually visit your site, or even know that your site exists? All the counter does is telling your visitors how FEW people are visiting your site. You don't even need one for analysis because we do it for you.
No. 1: I want ______ effect as well
Sometimes you may see some cool effects or features on other people's sites, and you just want to put a similar one on your site. Think first, does it help make your site better? Does it make your site rank higher? Will it affect the site speed drastically? Do you offer the same service / sell the same product as that person?
Reference Source: 10 Useless Web Design Features, part 2, part 3.