My primary concern with updating my blog is for
SEO. The blog ensures that I am #1 in google for every key phrase that my local potential clients will search for. As far as updating content to keep it fresh .. I update only when necessary. I don't post for every single client .. That would take time away from me making money. I post just enough that I maintain my #1 spots in google. Do my clients care if I don't spend all my time posting on it? Heck no. They are looking for a photographer "now" .. they are not hanging out on photographer blogs for the fun of it. They need to hire a photographer and that's the only reason they are looking at my site. The look .. they find me .. they make the call. I also do not waste time with strategies to encourage commenting on my blog. Will people commenting on my blog get me clients? Nope .. the photos they see are what makes them call. If I encouraged commenting all it would do is take away from time I could be spending making the moola !!!
You want to create repeat customers but creating interaction on a blog is not the way to do it. That is an area where you should be thinking about your customer service, thank you cards, packaging, etc. etc.