This has been a nagging void in e-commerce that people have been whining about (myself included) for 10+ years. I have plenty of products that I would sell for $0.69 each if it was economically feasible to do so.
Provided their service is good and the fees are reasonable, this could be a fantastic vehicle for online charity fundraising. It's a well-established wisdom that fundraising from a large volume of small amounts is usually more successful than than soliciting smaller volumes of larger donations.
Micropayments aren't a difficult concept. It's just a matter of pooling lots of tiny transactions into aggregate transactions. However no one in the banking cartel has had the kajones to try it, the popularity or infrastructure to make it successful, or the willingness to let up on predatory transaction fees that make it unfeasible.
PayPal is in an ideal situation to try this.