Using licensed music for video games became more popular as the medium used to distribute games grew large enough to accommodate songs alongside a game's other assets. Additionally, with the large growth of the video game market in the 2000s, song licensing became a lucrative route for music rights holders to gain part of that revenue. Games like those in the "Grand Theft Auto" series became showcases of licensed music. Music licensing is generally complicated due to various copyright laws, typically with at least two separate copyrights to consider: the songwriters' and the performers' contributions. Most large video game developers and publishers who use licensed music typically have staff proficient in licensing to clear songs for use in video games with the various music labels and other creative persons.