Getting visitors, and interviews, and other opportunities all stem from YOU taking your blog seriously.
Have a schedule - and keep to it. (Even if it's only one post a week - or a month.)
Follow through on your stated intentions. (If you have a survey for your readers, post the results!)
Be the kind of employee of your blog that you'd hire (Remember, in a one-person blog operation, you're the boss and the worker!)
And remember that if you act like a professional, you're on your way. After all, the first person you need to convince that you're serious is yourself.
On my journey, I blogged for more than a year at I'm Here. I'm Queer. What the Hell do I Read? before the tide started to shift and other people saw me as a professional, too.
And now, I get to blog professionally, as part of the Society of Children's Books Writers and Illustrator's SCBWI Team Blog. (I'll be leaping into action once again starting tomorrow when the 2010 SCBWI Summer Conference begins! Check out all the fun at the Official Conference Blog here.)
That's pretty awesome. And it all started because I believed in myself and my blog, first.
So Believe In Yourself.
...and Keep it Zen.