I know there's a 'thanks' button, but how about adding a 'like' button too? Quite often I've read messages that aren't actually responding to anything I've written but I'd acknowledge that I've read it and liked it. It might even just be a funny response that doesn't warrant a 'thankyou' but I'd still like say I enjoyed the response without actually typing out a message.
Was just a thought.
*Not to be confused with a facebook like.