Blog's readership has not measurably grown this year

For the first few years of its life, this blog's readership has increased by about 2.5x every year. However, this year it did not grow. Throughout much of the year, readership stayed on or around 2500 monthly unique visitors per month (total pageviews did go up from about 45k last year to around 60k in the first 49 weeks of this year, though, so that's …