There are several ways to estimate how much traffic a blog gets. Here are some free tools that will help you estimate how much traffic any given blog or website gets:

1) Compete.com - Go to this site, enter the blogs URL, and click on get site analytics. You will then see a chart with a monthly unique visitor estimate. Do keep in mind that this is just an estimate.

2) Alexa - Go to this site, and click on traffic rankings in top nav bar. Then, enter the domain name and click search. Then click get traffic details under the URL. This will give you the Alexa traffic rank. Basically, Alexa ranks every page on the web. For example, Google is ranked 2, Cnn.com is ranked 50th, and millions of other sites are ranked based on traffic. You may find you site to be in the top 100,000 or the top 1 million. Again, this tool is just an estimate, and not a guarantee.

3) trafficestimate.com - Go to this site, enter the URL, and click on Estimate. This will give you the estimated visits over the past 30 days. Again, use this tool only as an estimate