1. More space
Gmail launched with 1 gigabyte of free storage, an inconceivable amount at the time. For many e-mail addicts (myself included), this was reason enough to switch to Google's new service, putting pressure upon rivals Yahoo and Microsoft to upgrade their offerings or face a user exodus.
In June 2004, in response to Gmail's launch, Yahoo increased its storage limits from 4 megabytes to 100 megabytes. Hotmail, too, reacted to the Gmail threat by providing more storage: Some users saw their Hotmail limits increase from 2MB to 25MB.
In April 2005, Gmail raised the stakes yet again: Free storage was increased to 2GB, with a promise to increase the storage capacity available to users continually. In the same month, Yahoo Mail bumped its free storage up to 1GB. Hotmail played catch-up in late 2006, rolling out 1GB of free storage to users.
2. The perpetual beta
Love it or loathe it, Gmail popularized the use of the "beta" tag on many "web 2.0" products, indicating an early release that may contain bugs. The effect on Web development was at first a positive one: It became more acceptable to invite users to test the earliest versions of a product, and rapid development cycles became common.
And yet "beta" soon lost its sheen due to overuse: Not only did every Web startup co-opt the term to add "web 2.0 glitz" to a product, but Google itself devalued the term by leaving Gmail in beta for five years.
This extended beta period turned the "beta" label into a geek punch line of sorts. When Gmail left beta in July, Google conceded that "over the last five years, a beta culture has grown around web apps, such that the very meaning of 'beta' is debatable."
3. Conversation threading
Many e-mail clients now "thread" conversations on the same topic, but it was Gmail that popularized the concept.
Google says of the feature, "In other e-mail systems, responses appear as separate messages in your inbox, forcing you to wade through all your mail to follow the conversation. In Gmail, replies to replies (and replies to those replies) are displayed in one place, in order, making it easier to understand the context of a message."
It's a simple evolution that makes a huge difference.
4. Labels, not folders
Gmail's new way to sort e-mail seemed alien in 2004: Folders were replaced with "labels." If a mail was about both"art" and "design," a user could apply both labels rather than deciding which folder to place the message into.
Although this "tagging" concept was familiar to users of the bookmarking service Delicious, this new way to sort e-mail took some getting used to. Those who embraced it still swear it's the best way to organize your mail.
5. Archive, don't delete
Before Gmail, storage space was a scarce resource. Once you were done with a mail, you deleted it to save space. Gmail not only offered a massive amount of storage, but Google encouraged users to archive their e-mails for reference, rather than deleting them.
Google was so committed to this new paradigm that the "Delete" option was somewhat hidden. In early 2006, however, Google caved to pressure from users and added a more visible delete button.
6. Targeted ads
Considered a nuisance by some and a privacy invasion by others, Gmail scans your e-mails to deliver personalized ads in the sidebar. Whether the innovation was an advance or a step back is debatable: Before Gmail, Yahoo and Microsoft served up distracting banner ads alongside e-mails.
While Google controversially chose to target its Gmail ads based on the content of your e-mails, these ads were at least text-based and more easily ignored than those that came before.
In what other ways did Gmail change your e-mail experience? Let me know in the comments.