This is one of those nuts and bolts types of content sites. It's not really fun to write about roof repair, but it will be a good money earner and an easier topic to get higher search engine rankings in.
Type "roof repair" into Nichebot.com and you will get a lot of keywords that aren’t searched for a heck of a lot. It's still enough to be profitable, but its definitely not an over crowded niche when you get right down into the sub keywords.