It's almost monotheme to talk about WordPress.com but it's that Automattic are runaway lately with news, and today is – although it seems little – very important.
Well, from today you can already know, not only who clicks on the happy button of "I like" but also you can know who subscribes to your blog. This, which seems a nonsense is really important because it is the first step to manage the traffic of your site, build loyalty to your readers and even make online marketing, something that is not new but in WordPress.com.
The best of all (or not, according to taste) is that you will receive an email when someone likes an entry of yours or subscribes to your site, in order to track the popularity of your blog. Just go to the "Options -> Comments" page and check that the corresponding boxes are checked:
Of course, if your site is very popular it might be better to deactivate those options but do not underestimate the power of these ads. face to a personalized attention to the readers of your site, priceless for companies (did I say that WordPress.com is already becoming a great platform for corporate blogs?).