S.M. Entertainment's official press release regarding the group stated that the subunit's intention was to "grab the attention of fans with all aspects of music, performance, and fashion styles."Also hinting at the possibility of future subunits containing other members, elaborating, "by changing the members of the unit according to the music and concept of each new subunit album." The label also revealed the thought process behind naming the unit "Girls' Generation–TTS"”. The name "TaeTiSeo" is made up of the first syllables of Taeyeon, Tiffany, and Seohyun. This name has the letters "T" and "S", which have distinct sounds, giving a strong vibe of the team and also lets the fans recognize the members instantly.
A promotional image showing the three singers of Girls' Generation-TTS styled in outlandish clothing and makeup, with brightly colored textures around them, was released along with the unit's announcement in April 2012. Soon afterward, three video teasers of their single "Twinkle", each featuring a different singer, were released over three days, the total views for all three teasers reaching over 10 million on youtube within a period of four days.
The single "Twinkle" was released on the iTunes Store worldwide on April 29, together with its music video on the April 30, which attained over 10 million hits on youtube within its first week. The mini-album Twinkle was released on the iTunes Store on April 30 and on CD on May 2. They began promotions on music shows on May 3. Twinkle has also become the highest charting Korean Artist on US iTunes Charts and Billboard Charts, reaching 126 on the Billboard 200. TaeTiSeo, was also the first sub-unit to achieve a triple crown on all Music Shows. The album, Twinkle, has sold over 140,000 copies in South Korea, as well as a further 24,000 copies abroad. The title song has sold 1,988,373 digital downloads in South Korea, as of July, 2012.
TTS is the first ever sub-unit to win twelve trophies in their promotion period for Twinkle.
The sub-unit was announced to release their second mini-album, Holler, digitally on September 16 and physically on September 18 2014. Teaser images were released in a period of 3 days, with the images of a different member being released each day, One track from the album, Whisper, was released as a pre-release on September 13, sweeping up music charts. A highlight medley of the album was released on September 15.
The sub-unit was announced to have their own reality show, entitled The TaeTiSeo. The TaeTiSeo takes the viewers behind the scenes to unveil the human side of Taeyeon, Tiffany and Seohyun. Teasers of the show were released, with the first episode airing on August 26, 2014.