What companies are the most known profitable web companies/sites, the monster corporations aside? I recently read that a way to choose your start-up is to mimic/copy an already profitable site, and aim for a niche market.
Starting a website based on how profitable you think it is, or how profitable strangers on the internet tell you it is, is the worst idea I've heard in a long time.
What problems or repetitive tasks do you face on a day to day basis? Odds are others do too. Find a way to mitigate or address these challenges in a simple web friendly fashion. Evaluate the market to ensure your not getting into an overly addressed problem/task. There are so many things working against you when you clone or mimic a site. Take the easier road and contribute something new.
It sounds elementary and glamor free but it is a proven methodology.
I follow the needs of an industry. If you understand an industry, you can feel which direction to take it. I've never understood how or why people would use any other method.
Internet business isn't a get rich quick scheme.