Quote Originally Posted by Rtyom
I think so. З and Э are so close!

However, this mistake occasionally springs from the difficulty to recognise the two shapes.
I used to write Это as Зто for a while until I realised the difference. I didn't really think about it considering I knew how each were pronounced.

And, the online keyboard I just used shows Э as a З for some reason...

http://www.apronus.com/internet/ruskey.htm