I talk with people all the time that run blogs and wonder if they can sell products online with a blog site. I really don't think its a bad thing at all to be honest, (if done right, with the right software). For example; some sites start off as blogs and get big by accident. Lets say that you run a "hunting blog" and start to get a bunch of people asking your what you recommend for this or that. Perfect opportunity to find the product that you do recommend and sell it! It is much better to get direct access to the product as well through a supplier, rather then affiliate because you will always be making more money.
Don't forget about the readers that "launched" you and make sure you keep providing the great information they have come to love (and keep coming back to). I think you can find a good balance with blogging and making money selling products on a blog site. Its all about making money and you readers have to figure thats why you are doing it.
I guess the point of this post, is rather you are a new blogging site or old, think of all of the potential revenue streams of your blog and take advantage!