Pictures are an excellent optimization tool and a great way to attract attention. While Facebook and Twitter are still important to SEO, they are now joined by image-based social networks such as Pinterest and Instagram as ways to reach potential clients and generate conversation. On any social media platform or blog images are much more appealing than just text and they help you to create content that increases engagement! However, just like text, the search engines know what images are unique so be sure that as often as possible you are sharing unique images that belong to you.
If you are thinking to yourself "but I am not a photographer" or "I can't afford to be hiring a professional photographer" don't worry! There are lots of easy ways to create unique and visually appealing images. For example if you have a business, snap a closeup of a few of your products using your smartphone or take a picture of your actual storefront. If you are talking about your brand or service simply consider taking a picture of a stack of your business cards or a picture of you or your employees performing a service...
In order to optimize images to their fullest, choose carefully how you want to post them; find a picture that seems the most appealing to your target audience. That may seem like an obvious step, but keep in mind that 90% of casual social media users are considered "lurkers," people who simply watch their friends and do not interact; your goal is to give them something to talk about, something so interesting or visually appealing that they will feel compelled to share it with their friends.
TIP: Remember to use keyword rich descriptions (and hashtags when necessary) whenever you are posting or sharing to get maximum SEO benefit.