Mining has hit all time high now, lots of people like you and me have just started, it has changed difficulty to next level.
For example take ETC - I could mine 1.4 ETC a day last month, then after a week it has dropped to 0.9 ETC a day, last week it has dropped to 0.6 ETC per day.
But as long as the price of ETC keeps increase the earning will also increase but if it doesn't then you can go from $60 to $5 a month very quickly. (FYI ETC price fluctuated between $22 - $15).
This is gist of my analysis and my personal opinion.
Hope it makes sense.
Yes it makes sense.
Also, in last three years there was few periods when my mining operation was not profitable. But it made me to look for new coin to mine and this usually put me into profit later.