Mike Andrews is a character only heard on radio stations in Grand Theft Auto: San Andreas.
Mike Andrews is implied to be a motivational speaker. He had a show in the Los Santos Convention Center sometime in 1992, which the player cannot watch. He also wrote a book, called "Rags are Riches". He talks and writes primarily about how poor people must stop worrying about being poor and enjoy it instead. He also claims that the rich people (like himself) need the poor people, comparing them to Yin and Yang, respectively.
Ironically, he charges ridiculously large amounts of money to attend his shows and purchase his CDs, so it seems like a scam to make money.