Amen to that! I have come across several company blog posts where there is no direct link to the actual site. Clicking on their logo usually leads me right back to the blog.
Very annoying - For anyone else who gets annoyed with this - Clickable link - http://flattr.com/
I was JUST about to write the same thing! I see this all the time on blog.(app) sites -- annoys the hell out of me!
That said, I love the idea of this. A nice way to say thanks to people without having to go through paypal hell :D Might also inspire me to write more than "what I did on the weekend" blog posts ;P
If your blog post interests me and I want to learn about the product, it should be as easy as clicking your logo to get to it.