Most of the bloggers offer their readers the option to follow their blog. However, few blogger don't add follow gadget. I don't know what are the reasons but I guess it depends on blogger. Some bloggers are so popular that they get direct traffic. Like Rashmin Bansal would be getting lots of direct traffic just because her blog is popular and she is a very well know author and Youth expert. Her blog does not have follow gadget. Some blogs rank so high is search that they don't need repeating visitors. There can be various reasons for not adding follow gadget to blogger blog.
But some blog (like that of Rashmi Bansal) are so interesting that you may wish to follow it. So there is any easy way to do that. However you need blogger account to do that. I guess if you are avid blog reader you must be having a blogger account. If you don't have it..you can create it easily.
Go to your blogger account. You should see your blogger dashboard. If you don't have any of your blogs it would be empty probably. Just scroll down to Reading List area.
Just click Add
You will see the following box.
Add the URL of the blog you want to follow.
Choose if you wish to follow blog publicly or privately.
Click Follow.
You are done!