I suspect 99.5% of blogs like this don't make any appreciable amount of money from ads. Which begs the question, why even do it? If it cheapens your readers experience and you are not making significant money from it, just don't do it at all. Everyone thinks their blog will make money, few do.
Maybe I'm just lucky but looking at special interest blogs I appreciate the comments from other users/experts/makers. Diqus is the latest in a string of commenting tool and they all seem to have issues over time. A favorite blog resource of mine got nuked after the comments were filled with spam, and possibly used to hack the site. Unfortunately the blog was a collection of years of specific experiences in places with very little other information for that activity. I've talked to the owner about getting information in the years since and he's been helpful, but building the site back would take too long for him, so it's mostly gone. The comments there were useful for updates from people who visited those locations, or found alternate routes/approaches.
