The Internet is bigger than the lightbulb, but its effects are subtler (and colored by the massive popularity of porn, Facebook, etc.).
When I was growing up, I had two choices for getting “news”. I could read the newspaper each morning (which I did) and I could watch either network or local news on VHF (channels 2-13, for those who remember when TVs had dials). If I wanted to get a book, I had to convince my mom to drive me to the bookstore or the library. When I wanted to communicate with someone, I could use the rotary dial telephone or write a physical letter. Calling someone long distance was an unheard-of luxury. The only people I knew outside of my home town were our relatives. Now consider the world today. I can always access the latest news. I don’t even need to go to a computer, since my phone provides a conduit to the world. I can access pretty much any publication in the world for free online. My television has 1,000 channels, and the entire world’s collection of video is available online. When I want a book, I can order it and instantly start reading it on a handheld computer. And more books than in the Library of Alexandria are available for free. I can talk with anyone in the world at practically zero cost. For example, I have a certain friend who is spending some time in Chile–in my youth, I would have to rely on receiving physical letters via airmail to stay in touch! I have instant access to the thoughts and life events of hundreds or even thousands of people, and vice versa. I know people from places all over the world. In terms of access to information, interconnectivity, and the ability to publish to a global audience, I would argue that the Internet is every bit as transformative as the electric lightbulb or internal combustion engine.(Originally posted as a comment on this Ben Casnocha blog post on the slowing pace of change and innovation)