When a popular actor announces that he is going to be out of circulation for a while, he may be bombarded with lucrative offers. That's what happened to Song Joong Ki when he decided to enlist for his two-year mandatory military service in 2013.

The tVN show "E News" recently ranked him as #5 in the list of the top celebrities who made a considerable amount of money while serving in the army. Before Song Joong Ki joined the army on August 27, 2013, the 29-year-old actor received more than 10 offers for TV commercials. He signed contracts for commercials featuring cosmetics, sporting goods and phones. He earned about $500,000 for each modeling contract.

And that was just the money he earned before he enlisted. Because of the way he chose to serve, he became an even more desirable commercial spokesman.

Previously the Korean armed forces had a special unit for entertainers, who might serve their two-year duty performing or carrying out promotional duties. But a scandal, which involved singer Se7en, became the focal point of citizen outrage over celebrities abusing the system. The singer was spotted at a massage parlor while he was supposed to be on duty. As a result of public pressure, the celebrity unit and its alternative options for serving were eventually abandoned.

Song Joong Ki chose to join the army as a regular soldier and his not wanting any special treatment made him even more popular. The actor enlisted at the 102nd draft camp in Chuncheon and served his time in the Reconnaissance Corps. This potentially dangerous assignment required intensive training. The Army recognized his service and he was asked to host a special promotional event in China for the Ministry of National Defense.

But Song Joong Ki's service did not interfere with his ability to earn money as his contracts for his pre-enlistment commercials were renewed while he served.

Song Joong Ki is known for his performances in the melodrama "Nice Guy" and historical dramas such as "Deep Rooted Tree" and "Sungkyunkwan Scandal." He made his debut in the film "A Frozen Flower" and played the leading role in the popular film "A Werewolf Boy." He is scheduled to finish his military duty in May 2015.

According to "E News," other celebrities that continued to earn well while fulfilling their military service are Jang Hyuk, Yoon Si Yoon and Ji Sung.