I initially started my blog with the intention to talk business-only. I posted like, once a week and had little to say. In the end I started talking about me, my life, my aspirations and crafting, and that's when the views and followers started rolling in. Two years on, it's firmly a personal/craft/writing blog, but if I ever have any news about any of my businesses - new products or exciting happenings - I share them on my blog. I do make sure to post last Christmas posting dates on my blog, too, and I have flash sales exclusive to my readers, so I make sure my readers know what is happening, but otherwise, I have very little to talk about regarding my business.
I've made a few friends through my blog, and that, in turn, has gotten me sales as well. I also know that I am more likely to buy from people who I consider to be my friends, because when you get to know them, or why they do what they do, it makes it easier to relate to their products and want them all the more.
This is my blog: www.ablackbirdsepiphany.co.uk It was originally named Peaches and Pebbles Weekly but, well, I hated the name, too! Just make sure you create a tone for your blog and stick to it. Don't talk about things that are controversial. If it's just going to be a personal blog, and have nothing to do with your business, you can say what you like, within reason, but if you're tying your business to it that tightly, then saying something controversial or ignorant can have a huge impact on your business. So don't talk about things you don't understand. Stick to you - what makes you tick, what makes you happy, day-to-day life and crafting tutorials (not necessarily anything to do with YOUR craft. You'll never find me posting anything about how to make jewellery on my blog).
Basically, blog smart, but blog you.