I like to use the classic example my mom once taught me, in which a will was to be divided equally between three daughters – “Jessica, Mary and Emily” – and this was interpreted to mean that Jessica got half and Mary and Emily got to split the other half. If they were a couple, you’d write it like that, right? But in the end, I think this might be a better the best way to explain the problem with removing the Oxford (aka serial) comma.
Jeff Bishop, via the Language Log
Now, how can I share this with my clients without getting yelled at…?
Sally and the City 
This is by FAR my favorite of all your Blog posts ever! I’ve always loved & supported this rule and loved your mom’s “will” explanation of it. I never knew it was called the Oxford Comma.
I know! I do not understand the argument against the Oxford comma – it totally breaks down the distinction of having commas in a list in the first place. I actually showed this to my boss while making this argument the other day.