Sometimes when my customers click the Facebook Like Button, the image posted to their newsfeed is not the product image. How can I ensure it is always the relevant product image.
It's important to specify an Admin ID (or multiple admin IDs). Visit Settings/Compatible Software/Social Networking Preferences and add your Facebook ID. If you login to Facebook and click "Profile" your Facebook ID should be the far right portion of the URL.
You might also check Facebook's Open Graph Debugger tool, available here https://developers.facebook.com/tools/debug.