I used to ride a piece of junk Walmart bike once in a while, but in one year I have gone to being a fairly regular commuter. Thanks to BikeForums, I was able to buy the right bike ( dahon D7 from Craigslist for $150 ), good lights ( Fenix flashlight $60 ), good tail lights ( Planet bike superflash $17 ), right mirror ( Take-a-look eye-glass mount mirror $15 ). I bought all these online . All these products provide superior performance at relatively affordable prices.
Without Bikeforums, I can only imagine it would take years plus a lot more money to evolve into being able to buy the right equipment for your needs. Sure you can walk into a LBS and buy the top-of-the line for everything, but you'll end up paying a lot more than I did. Also most expensive doesn't always translate into best.
What did people do before BikeForums existed? I suspect they just made do for years with whatever crappy equipment they could afford and never upgraded? I guess knowledge really is power.