January 31st, 2010 - I start my addon programming days with an addon called Slippy. This addon is inspired by Quick Auctions 3 and fills in the missing capability of QA3 as far as creating enchanting scrolls.
April 8th, 2010 - Slippy gets a new name, Scroll Master.
October 11th, 2010 - I create Auction Profit Master, a continuation of the now discontinued QA3 addon which was abandoned due to the new hardware requirements on posting and canceling of auctions.
November 27th, 2010 - At this point, all major gold bloggers have been informed about this new TradeSkillMaster addon that's in early development. The addon is featured in this JMTC post by Marcko. This same day, we begin inviting people (initially focusing on bloggers) to become alpha testers. The initial alpha version contains the AuctionDB, Auctioning, Crafting, Mailing, and Shopping modules.
December 5th, 2010 - First alpha version of the Gathering module released. This is the last new module before TSM is released as Beta.
December 7th, 2010 - Cataclysm is released. This date was the original (very optimistic) target beta release date.
January 15th, 2011 - TradeSkillMaster finally released to general public as beta! Over the next few weeks, literally hundreds of bugs are fixed as tens of thousands of people start using the addon. The addon is also featured on many key gold blogs.
January 22nd, 2011 - TradeSkillMaster gets an official, dedicated forum at The Consortium.
May 5th, 2011 - At this point, TradeSkillMaster is relatively stable and has earned it's spot in the gold making community. The 8th module (including the main one), Accounting is released for some early testing. Accounting was released as beta 2 weeks later.
May 23rd, 2011 - The 9th (and currently most recent) module, Destroying, created by Geemoney, is ready for alpha testing and is released as beta 5 days later.
June 1st, 2011 - At this point, TradeSkillMaster is very stable and countless new features have been added since it was first released as beta four and a half months earlier. Work now begins on one of the biggest new features planned for the release version of TSM, the new auction house tab. Work on the release version of TSM (including this new tab) continues to this day!
While I don't have accurate numbers as to how many people use TradeSkillMaster, I do have data as to how many people use each of my addons relative to each other that I thought I'd share. From highest to lowest: TradeSkillMaster, TSM_Crafting, TSM_Auctioning, TSM_AuctionDB, TSM_Shopping, TSM_Gathering, TSM_Mailing, TSM_Accounting, TSM_Destroying.
Without sounding too sentimental, I really enjoy working on this addon. Watching it grow from a far-fetched idea into what it is today has truly been rewarding. There have been hundreds of people who have helped along the way that I'd personally like to thank. This includes everybody from the initial alpha testers to the bloggers to the people who have contributed code to everybody over at The Consortium to people who stopped by the forum or IRC to provide feedback.
Here's to another successful year :)