People think that serial / “Oxford” commas should be an optional style thing. But if you’re writing for the web, please use it.
Here’s an example of a sentence without a serial comma:
Please bring Jack, your brother and your uncle to the party
And an example of a sentence with a serial comma:
Please bring Jack, your brother, and your uncle to the party
First point: the second sentence makes it much clearer that Jack isn’t some questionable relative and that you’re meant to bring three people to the party.
Second point, and more the point of this post: the sentence with the serial comma is much more intelligibly read by screen readers, particularly when content is being read quickly.
Use the serial comma!