Answer: Gmail

What Gmail offers—lots of storage, a raft of features, and all at the very affordable price of free—is just something we take for granted today. Back in 2004, however, the landscape of web services and free email looked different, and what we expect as routine in the present was outlandish.

In fact, Google, rather tongue-in-cheek, timed the release of Gmail with April Fool’s Day specifically to pull a sort of meta April Fool’s Day prank. At the time of launch, Gmail offered one GB of free storage when other providers were offering a few MBs of free storage. To say the public was skeptical of the announcement would be an enormous understatement. The tech community reacted as if it were a prank, through and through.

The real prank, then, wasn’t convincing everyone that Google was offering an improbably generous free email service, but actually offering it.