It looks like you were quite committed to make the $100/month after a year. Great job. A lot of ppl quit after a month or two of not making any money with Adsense. With more original content, promotion and building backlinks, you'll increase traffic and in turn, increase $$$.
Great Job then, consider yourself lucky because other bloggers tends to reach the $100 dollar earnings in 2 years!
Here's a quick inspiration exercise. Go to adwords keyword tool. Type in your core topic of your current blog and adsense brings up lots of alternative terms. many of these are related but not exactly the same as your blog. These are topics that you could write new copy about. I find this and dictionaires great ways of finding new topics to write about.
Lol, $100 a month is a mazing, I have had my sites for a few months now, I have three altogether, 2 are just recently opened but I have altogether earned $0.70 !! Lol, but I am slowing getting a few cents a day now So count yourself lucky, I will never reach $100 a year even! Well Done! (maby you could give me some tips lol)
Here's the secret to making $1000 per month... Do it TEN TIMES. No, I'm not trying to be funny. I'm serious. If you can make $100 per month with one blog, repeat that success 10 times, and you will make $1000 per month. Or, make your current blog earn $200 per month, and repeat 5 times. Whatever the math is...
Blogging has limitation from money making point, unless, you can really make yourself stand out. You may like to enter into some kind of programming or intelligence to go to next step.
Start a new blog. If you are earning $100 from one, and running out of ideas it would make sense to start another one about something else
Well done on reaching the $100/mth mark. I've found that the niche you target is really important. I've got 2 sites in the weight loss and finance niches that are making $2-$4 a day on just a few clicks a day.
Those are actually good figures considering the competitiveness of your niche. I2m sure you'll make more a couple of months later.