It's because I'm writing a book this month.

I swear I'm not a grammar Nazi, but I do appreciate it when people can use proper grammar and spelling. It helps to enable clear communication, and I like it when the focus is on the ideas being communicated--not on a search for the point of failure in communication.

Therefore I present for your perusal this link to an article on the finer points of using 'i.e.' and 'e.g.' in writing: How to Use "i.e." Versus "e.g."