Another reason is that if you're using an image as a link, the alt text for that image will be treated similarly to the anchor text of a text link. However, we don't recommend using too many images for links in your site's navigation when text links could serve the same purpose. Lastly, optimizing your image filenames and alt text makes it easier for image search projects like Google Image Search to better understand your images.
Since heading tags typically make text contained in them larger than normal text on the page, this is a visual cue to users that this text is important and could help them understand something about the type of content underneath the heading text. Multiple heading sizes used in order create a hierarchical structure for your content, making it easier for users to navigate through your document.
My favorite style in this is article marketing. You create anchor content on your website or blog, then you build authority-content links to that content, effectively driving up the visibility. I've used this single strategy to rank hundreds of keywords in the #1 spot on Google, and I would highly recommend that if you're going to learn any marketing strategy, that you get really good at this one.
Poor User Experience: Make it easy for the user to get around. Too many ads and making it too difficult for people to find content they’re looking for will only increase your bounce rate. If you know your bounce rate it will help determine other information about your site. For example, if it’s 80 percent or higher and you have content on your website, chances are something is wrong.