Register now or log in to join your professional community.
A lot! It enhances your content; it breaks 'the ice'; it reinforces the overall topic, etc...
Human beings are more affected by what they see rather than what they read. Images help to convey a message effectively. "A picture says a thousand words" gives more than a compelling reason for a blogger to use images in their blog posts.
More importantly, images are highly preferred by Google and an image with proper SEO can do wonders for your blog.
For example, Infographics are great a way to grab attention. They are easy to share as well and are visually appealing. These three things combine to create a fantastic content.
Do not ignore images. Try to have unique images. Stock images, although a bit helpful, won't help in conveying a message as effectively as a unique image.