I'm thinking of getting into this. But I'm wondering if Penguin / Panda has affected the marketability. Has the demand for keyword based articles gone down?
I am not pretty sure but yes it has gone down keywords used least or I guess only up to 4% are going up..
It definitely has. The demand hasn't gone down, possibly even up, but the demand for lower quality, cheaper articles has gone down significantly and people realize now these kind of articles do more harm than good. So if you're in the article writing services business try to improve the quality of your services and raise your prices.
Well i am not 100% sure about Google Panda/Penguin has effected the Articles website because article website has policy to write article so i dont think so it would effected through Panda/Penguin.