I have already many times on my blog expressed my concerns how Google treats my sites (especially one of them)
I have noticed some strange organic search patterns in last month. And yesterday traffic stopped at all. I received traffic just for 30 days. Seems Google gave me some time, and then decided to block again.
Another option I guess, I might get banned by Adsense above the fold ad placements. So I have removed them from that site, and will limit ad placement in other sites as well.
If that won't help - I will for sure abandon that site and pick another niches to work on.
I already have an idea - to limit my expenses for hosting and earn from Adsense. I should take a new VPS to put on it some new niche sites. I guess I will downgrade my existing Linode VPS from $40 to $20, and buy some cheap Digital Ocean VPS for $5, making my hosting expenses $25, instead of $40.
As said - I'm thinking for more niches this year. Another challenge?