I had been getting a little concerned that our email list numbers have been levelling off. Then I looked at our RSS feed numbers, which have been taking off. If you add the two together you see a firm upwards trend. This corroborates the comments from people who unsubscribe - many of them say they're switching over to RSS. One day I may replace that number at the top left of our home page with a new number. Or I may just say something like "Over 15,000 people read Unshelved every day" which will help me not obsess over said number.