Idol groups with ten members or more are uncommon, but not unheard of. That may be due to Super Junior's success in the K-Pop industry.

In 2005, when Super Junior debuted, there was bafflement over the fact that SM Entertainment would try to produce such a large group. 12 members was unheard of, and then they added Kyuhyun, to make thirteen. With the two Super Junior-M members, Henry and Zhou Mi, most critics couldn't fathom Super Junior being a long-lasting group.

The reasoning behind all of the naysayers was that even five-member idol groups fail- how can one with more than double the average amount of members last? Most groups break up because of internal conflict, or members deciding to leave to pursue their own individual career. 

In addition, the media suggested that so many members meant that fans wouldn't be able to pick favorites, or even learn all of their names. 

Super Junior also had one thing working against it- it debuted as Super Junior '05, implying that members would rotate in and out (much like After School's graduation system.) That concept was thrown out shortly before Super Junior became extremely successful, revealing that SM did indeed think that Super Junior failed in that way. As a result, since then SM has not promoted any groups with member "graduations."

But while the graduation experiment failed, the large number of members proved to be Super Junior's saving grace. 

Thirteen members was, on SM's part, a huge leap of faith that could have gone horribly wrong. And, at first, it appeared to do so. But slowly Super Junior began to gain momentum, with songs like "U" and "Don't Don."

However, in 2009, during the phenomenal success of Super Junior's "Sorry Sorry," it seemed that it would all crumble apart. Hankyung (Han Geng) withdrew from the group, citing disparity and unfairness in his contract, in part due to him being from China and without proper legal representation.

Super Junior stopped activities for a time, and there was a lot of outrage from fans both towards and against Hankyung- some people were proud of him, and supported his efforts to get a more fair contract, while others said he was being disloyal.  When it was clear that Hankyung was leaving for good, it seemed like Super Junior would fall apart together.

As this was all happening, fans also noticed that the member Kibum wasn't promoting, and only appeared in Super Junior's music videos minimally, but never sang. Kibum's departure from the group didn't mean disaster, possibly because Hankyung's role in the group, as the sole Chinese member (the first Chinese K-Pop idol,) he brought a lot of fans to Super Junior. Hankyung was also the leader of Super Junior-M, meaning that the subgroup would need to reorganize to become more China-friendly.

It didn't look good, but Hankyung wasn't one member out of five. His departure left a gap, but Super Junior had other members who could dance, sing, speak Chinese, etc.

Fans still would like to see all thirteen members on stage together, but the departures of Hankyung and Kibum didn't leave the stage completely empty. 

Even though it was a hard time for Super Junior, the fact that there was both a contract dispute and a member quietly leaving proved that, no matter what, numbers actually worked in Super Junior's favor. A big scandal didn't hurt, a major player in the group leaving didn't affect it immensely, because there were other members to take up the roles.

When Kangin got into some legal issues involving public drunkenness, DWIs, and fighting, again people worried that Super Junior would be done for. But, again, it proved true that a member leaving wouldn't be the end of the group. Instead SM tried another experiment- rotating members into and out of their military service. 

Leeteuk's recent return from the army, returning as the leader of the group, highlights once again how Super Junior's strength is its size.

So far, three members of Super Junior have left and completed their military service to return; currently Yesung is in the army.

Is it awkward that one of the main vocalists of Super Junior's in the army? The upcoming seventh album will probably show that no; there are enough talented singers in the group that there will be no problem. Yesung's unique vocals will be missed, but Super Junior has ten active members.

Super Junior was the first experiment to test the limits of K-Pop groups and size. Since then, there have been large groups like Girls' Generation, EXO, ZE:A, 9Muses, etc.

Instead of being too large for stage, too large for fans to follow, Super Junior's numbers have saved it. The multitude didn't keep Super Junior from becoming one of the top Hallyu groups, but it did keep the group from falling apart when there were scandals and members withdrawing.