Why track it at all
Because side income is lumpy and memory is kind. Ads pay small amounts on a delay; a client pays three invoices in one week and nothing for a month. Writing the real figures down each month is how you find out whether a thing is working — and how you stop telling yourself it's going better (or worse) than it is.
How I use it
On the first of the month I log the previous month's AdSense payment, client invoices that were actually paid, and anything else. I look at the six-month bars, not the month. If a source has been flat for six months, it's time to change something or stop.
