This one is for both those in front of and behind the camera. For photographers, having a blog is pretty much an absolute. A good blog can be an asset to your business. I love posting session sneak peaks, and showing new products (something so exciting coming this week). I posted a few of my favorite photography blogs recently (Inspiration) and I think they are great examples of how to successfully blog.
For families, personal blogs can be a great way to keep friends and family updated, especially when families are separated by distance. Grandparents love to see and read about their grandkids, and blogs can be a very easy way to do that. The other really great thing is you can make your blog into a bound book (blurb), and it becomes a great family journal.
Here's one reason why I love to blog. My BFF is having a baby. I met Sally freshman year of college. We lived together for 3 years and then unfortunately moved after college due to jobs and school. I came down here to Philadelphia. She went to Massachusetts, then Albany NY and is now finally settled in Roanoke Va. I don't get to see her nearly as much as I wish, but through this blog, she's able to keep up with my life and I can share this photo of her to all our college friends! So, here she is, cute belly and all.