One popular reoccurring post on blogs, regardless of niche, is an income report. For instance, MyBlogLift has a monthly (well, two) income and traffic report. Cash Flow Diaries has a long list of different income reports.
In an ever long pursuit to diversify my income (I’m already signing up for checking accounts just for the bonuses as well as buying and reselling things on eBay), I’ve taken up the hobby of designing t-shirts. I only have three so far (well, I have a first one, but it was more to learn the platform), and none have sold. Not surprising since I only launched one yesterday and two today.