Is Writing For Suite101 Worthwhile?

My page views have now stabilised at around 250 views a day, which I am very happy about. However, I am finding that my revenue changes massively from day to day. In the last three weeks a very strange and unexplained pattern has appeared. On Monday and Tuesday I make a lot (by my standards) of revenue, Wednesday and Thursday and Sunday almost nothing, and Friday and Saturday somewhere in between. I have no explanation for this variance but would love to hear people’s thoughts.