So, how do I change that Facebook thumbnail image?
Okay, so the other day I was sharing a link on my Facebook page, and the thumbnails were, as usual, ridiculous. I have nine to choose from: #1 is a hot tub, #8 is the logo, and #9 is, inexplicably, the navigation.
You can see below our link is shared with the banner for our homepage and not our logo.

Now, when personally sharing links with friends, this is an excellent opportunity to joke around and pick the strangest one. However, when it’s your blog article or your business’ site, chances are you want your business to be represented as best as possible.
So, how do you do this? Well, you can force the image that Facebook uses for links by adding this snippet to your metadata (if you don’t know what this is, ask your developer or web person):
<link rel="image_src" href="http://www.yourdomain.com/your-thumbnail-image.gif" />
After adding that code to our site, now all our thumbnails for sharing are forced to have our logo!
Speaking of meta data, this brings me to my last friendly little point: please make sure your site has an updated, relevant title and description. This stuff is seen by search engines, real humans, and Facebook-sharers. So, don’t let your viral marketing opportunity be skewed; make sure your links are shared and spread the way you want with the right brand and right message.


[...] what if your site is designed in a way that your logo is not one of them? Well, there is a way to fix the Facebook thumbnail, but we ‘ve made it simple in WordPress by allowing a user to upload multiple images and [...]
Big thanks for this! I actually typed in, “how to change the logo that comes up when sharing a link in facebook”
It worked! Thanks.
[...] are two ways to handle thumbnails, depending on your needs. Ask Insiva has identified one easy methodology. If you only want a single image to be displayed when a person [...]
This worked great for me, thanks. The post in comment 3 had some really good details, too, since it says how Facebook picks thumbnails and how to resize yours/etc: http://nowsci.com/techviews/20091215/set-your-pages-thumbnail-image-for-facebook/