Girl's Day announced this week that they will be the next long-established K-Pop group to release their first full-length studio album.

In the past several weeks, fans have welcomed similar news from Rainbow and Teen Top with much excitement.

After years of singles, mini-albums, and live performances with no concrete album to show for all the hard work, these first full-length releases give the groups the clout they need to compete in the market.

Single and mini albums only give fans a handful of catchy songs at a time, and while they are good for promotion and performance on live shows, they do not provide listeners with a good sense of the idols' full range of talents. In a full album, however, the artists have the opportunity to shine in a variety of songs that showcase their many different abilities.

That said, what are we to expect from the adorably sassy ladies of Girl's Day?

Expectation is their aptly named first studio album which will contain 14 tracks - six of which are brand new songs. The album will also include five previously released singles, two instrumentals, and one remix.

According to Girl's Day label, Dream Tea Entertainment, the girls lent more than just their voices to the project. Member Sojin actually composed the intro to Expectation called "Girl's Day World" and all of them contributed to the new song "I Don't Mind."

The track, "White Day" was released as a single last month as a prelude to the upcoming album.

Since Girl's Day debuted in July 2010 they have released three EPs and six digital single albums. Expectation is set to be released March 15.

They are following the recent trend started last month by Rainbow, who also released their first studio album years after debuting.

Rainbow Syndrome - Part 1 came out on February 13, more than a year and a half after their last Korean release as a group.

The album is cohesive and the songs are tailored to the vocal strengths of each of the seven members. It does however, differ quite a bit from their previous singles which have been described as fiercely sensual. Rainbow's studio album focuses on their soft, silky voices and the songs are generally pretty girly.

Rainbow Syndrome was produced and executed well and gave fans a different side of Rainbow, expanding the notion of what their signature sound is.

There is still no confirmed release date for Part 2.

Teen Top was not far behind Rainbow and released their first full-length album, No. 1, on February 25.

The six member boy group debuted under T.O.P. Media in July 2010. Their first single, "Clap," received positive reviews and they were also praised for their choreography.

Unlike Rainbow, however, Teen Top's first album stayed true to their style.

For No. 1, many of the songs offer up the hard-thumping dance pop the guys are known for, but there are sprinklings of ballads and R&B for balance, and as a whole it is an exceptionally diverse album.

Differing from the soon-to-be-released Girl's Day project, Teen Top did not include any of their older songs on No. 1 - every track is brand new, and the album is a fresh start for the group.

Especially the title track, "Miss Right," encompasses all that is needed for a successful album and an exceptional comeback: it is extremely catchy and has stellar choreography.

Teen Top previously released four single albums and three EPs.

We can only hope that more of our favorite artists continue this trend and release new, full-length albums with a wide-range of options for fans of all shapes, sizes, and tastes.