3) Luck. Don't use it as an excuse, but be aware that it can mess you about. But also remember that the harder you work, the luckier you get.
Fortune favours the brave.
It's a good point and essentially about the misunderstanding of the nature of randomness. When two groups of people are told to write down the results of 50 consecutive coin tossess the reason it can be immediately identified which group were actually given a coin and which group had to make the results up is because that the latter never dreamt that you might naturally get 8 tails in a row. Randomness alone means a business that was inundated in Jan 2014 may be checking the phone works in Jan 2015.
In a sample size of one business, expect dramatic and worrying fluctuations just as a matter of course.