When a user clicks the facebook like button several bits of information about your web page is submitted to facebook. One of these is the URL to an image that will be used as the thumbnail on the users facebook profile for your web page.
The plugin automatically sets the featured image, if one is available for your blog posts. In the event that there is no featured image, rather than having facebook automatically select what it thinks is an appropriate image from the page content (something which it isnt particularly good at yet!), you can set a default image, which will be used instead.
The “Default Facebook Image” can be any image at least 50px x 50px and with a maximum aspect ratio of 3:1.
To add a default image just enter the full URL to the image file in the “Default Facebook Image” field in the plugin settings page.
If you are having problems getting the facebook like button to work, make sure that the default image is set.
total
twitter
facebook
google +1
linkedin
stumbleupon
digg
delicious
pinterest
reddit
Great plugin, I have it working perfectly for a blog based on a template but strangely is not working for another, whenever I activated is sent to the bottom left part. have a look http://www.luxuryssimo.com/2011/top-5-most-expensive-shopping-streets-in-central-eastern-europe-2011/
Is it incompatible with some templates?
No, its fully compatible. The template may be coded incorrectly. See faq for more information