Updating a blog regularly does have advantages, providing you have the time and the inclination of course.One of these advantages is that your blog will be spidered more often by Google. I have found this to be the case on a couple of blogs which I update at least once a day.
"So what," you may say.
As I see it the more often your blog is spidered the quicker you get seen in the search engine results. In the past, where I have followed hot trends, I've had a number one or two ranking on Google within one or two hours of posting.
If you can therefore get in on an early trend, something on the way up, it can pay dividends in the way of big traffic. I did this with a celebrity story, on a blog I update regularly, and got over 40,000 hits in a day which were mainly Google referrals.
So, yes, a regularly updated blog, with the right content, can help towards making a decent income from blogging.
Good luck,
Mike.