Answer: Gmail

Looking back from the present, where Gmail is the world’s most popular email service, it seems almost implausible that upon its launch, it was scoffed at as a bit of foolery.

Implausible that is, until you realize Google launched the service as a beta product on April 1, 2004. For a brief moment, the entire world was incredulous at the idea of the search giant getting into the email business and wrote the entire thing off as a tech-centric April Fools’ Day prank. If that doesn’t seem like much an April Fools’ Day prank, consider the context at the time. The leading free email provider was Hotmail and a free account came with a tiny 2 MB of free storage. (Yes, you read that correctly. 2 MB, as in barely more storage than a 1.44 MB 3.5″ diskette).

Gmail’s announcement, which was written in a light-hearted jokey language that you might expect from a joke, indicated that free accounts would come with a whopping 1 GB of storage, an amount of free storage completely unheard of at the time. You can understand how people were more than just a little bit incredulous that Google was suddenly offering an email service with 500 times more storage than the competition. To put that into perspective, that’s as if, today, some company emerged to compete with Google and offered 7.5 terabytes of storage for their free account.

Everyone sobered up quickly, however, and getting into the exclusive invite-only service that offered more space and more features than the competition was a huge focus for a lot of geeks the world over for the next few months. While getting a Gmail account isn’t a big deal these days, back then, it was a big deal to get in and use your sparse invites to help your friends nab a Gmail account.