Are Micro Niche Sites still profitable?

I know its a whole lot harder now

There's ways to make money with Adsense other than MNS and authority sites. Be creative.

I bought something like 35 MNS a couple years back. The majority of which never ranked. About 3 of them or so bring me in ~$100/month total with no effort what so ever. I have never added any content to them or had to rank them. Eventually I'm pretty sure they'll drop out of the SERPS, but they're not doing too bad for me right now.