Carlill v Carbolic Smoke Ball Co. (1892)

I just had a 3am coffee and my brain's still foggy, but I remember this case for sure. So, Carbolic Smoke Ball Co. advertised a product, a smoke ball that prevents influenza. They offered a prize to anyone who died after using the product. Lady Carlill used the product, got influenza, and died. Her husband claimed the prize, but the company refused, saying she hadn't given them notice before using the product. The court upheld Lady Carlill's claim, saying the advert created a unilateral contract - you use the product, you get the prize. My question is, community, what do you think about this judgment? Do you think the company's advert created a valid contract? Was it fair to them to pay out the prize?