At least two people now have read my blog and set up their own businesses. One of them practically Xeroxed my business, and his I-can't-believe-its-not-me is fairly decent. I always joke that since my sales have doubled since then all I need is to recruit two more people who understand copy/paste and then I can retire. (The numbers in the joke are way out of date.)

Similarly, I was myself a new upstart competitor to the established market participants back in 2006, and I haven't killed them, either. (The idea is not to pick a market with no competitition -- that is a red flag there is no money to be made. Instead, pick a market where there is an addressable niche for whom the existing choices are painfully inadequate. Then, sell pain relief.)