Spelling Errors: Stupid? Lazy? Or A-OK?

[Alex]

Originally Posted by JWBear

Every writing class I have ever taken taught that it is proper usage to include it. The practice of omitting it was started by newspapers in order to save space.

Here's a good presentation of the argument against, one that is accepted by many English speaking countries and the majority of American non-academic styleguides (which, as you suggest, are primarily newspapers and magazines).

Personally, I use the serial comma, but I agree with the con argument that 90%+ of the time it serves no functional purpose and so to the extent that a rule is needed it should be simply that the comma is mandatory only when its use eliminates ambiguity.