If you blog professionally for any length of time, then you’re going to start hearing about things like Alexa and Klout scores. People will tell you that if you want to survive and make money, then you’re going to have to have good scores.
Who knows, in five years these can be completely replaced by something new, but in the mean time you can focus on these. Your Alexa score is your website's general popularity based on both a national and international level. They don’t judge you based on niche or classification, so you’re being judged against everything.
The lower your Alexa score the better your global and national popularity. Think of it as your score represents how many sites on the Internet are more popular than you. The lower the number, the smaller the number of websites that are more popular than you.