Keyword trends in affiliate marketing do not stay the same for a long time, especially in niches like tech, finance, and health. New products come out, prices change, and people start searching for new things. Because of this, it is important to check keywords often and see if search interest is going up or down. From what I have noticed, some keywords stay useful for years, while others change within months, so how often should keywords be reviewed in a normal affiliate site to keep traffic steady?