Add alt tags to all your images in this way, describing the image in a short sentence. This will help search engines associate your site with particular Key Phrases & Keywords and subjects. You may also get traffic from searches via Google Images.
In a similar way, videos are very prominent in Google search results and YouTube is considered by many as the second most popular search platform on the web. Rather than trying to host and play video files on your website, make use of the YouTube platform and embed the content directly from there. Not only will this give you the benefit of faster-loading content, you’ll also be broadening your audience.
Any other content types can be optimized in the same way – for image galleries you might use Flickr, for audio you might want to use Soundcloud, and for presentations you could look at Slideshare or Comslider. There are dozens of possibilities, so do a little research and pick the best suited for your needs.
Something else to try
A single piece of popular content can attract more traffic than the rest of your pages put together – creating a quiz about pop-singer’s hairstyles might not exactly fit with the rest of the content on your site, but if it pulls in the traffic then it might be worth considering…Seriously, merging some site content with popular content can be in-directly effective.