I have a habit of over-thinking things on occasion so please tell me if I'm doing just that.
First of all I'd like to say I dislike the Ellis Mars theory because he doesn't seem superior to Jane in anyway, isn't charismatic and is quite repulsing. I also don't think the actor could possibly pull off such a powerful character as Red John even though he was excellent at portraying Mars the way he did. But I can't help see certain clues such as the little tiger on his business card, the Elliston farm. Also, there is a crater on Mars that looks similar to a Red John face - google 'Galle Crater on Mars.'
Also, mars is also known as the red star.
'Tiger tiger, burning bright,
In the forests of the night...'
The forests of the night could be defined as the sky and Mars is what is burning bright. Far fetched? Quite possibly.
