According to the conversation, the day is special because

M: Hello, Eva.
W: Hello, Bob.
M: You know today is a very special day, that is, the 20th anniversary of the World Wide Web.
W: Ah, the World Wide Web. It’s really changed our lives and —and in such a short space of time.
M: Uh, definitely. Now do you know on average how long does someone spend surfing the net each day?
W: Um, honestly I don’t know, but I guess people must spend a lot of time on things like Facebook.
M: That’s true.
W: And I’m sure almost everyone uses the internet now, but I wonder how we cope without it.
M: Well, that might be a bit difficult without it.
W: I guess so. For instance, some people need it for social relationships.
M: Yes, especially those who are far away, keeping in contact with friends and family would be impossible without the internet.
W: But other people who would cope without the internet?
M: Yes, they are. These people have some alternatives.
W: What kind?
M: For example, we could write to each other like we used to before we have the internet. It would be lovely to get more handwritten letters from friends and family rather than just e-mails, I think.
W: That is what we call Snail Mail, of course, lots more paper would mean that we need bigger file cabinets.
M: Yes, well, it ’s still incredible how the World Wide Web has expanded in 20 years and how much we now rely on it. I wonder what it would be like in another 20 years.
W: Well, for better or worse, the Web will have a greater impact on our life and society.