Ideally, you’ll use all three distribution methods. You know your audience and hopefully you know how they’ll respond to your video. Focus on the distribution method that’ll give you the biggest return. If you’re in the film industry, focusing more on paid distribution might be your best bet. If you’re in the field of cancer research, earned media might be the way to go. Are you an entrepreneur that just launched your own startup? Spread word via your owned channels. It all really depends, so do a little research and see what fits your situation best.
Professional cameras, like DSLRs, give you fine control over the manual settings of shooting video and allow you to achieve the shallow depth of field (background out of focus) that people rave about. While they're primarily used for photography, DSLRs are incredibly small, work great in low light situations, and pair with a wide range of lenses — making them perfect for video. However, DSLRs do require some training (and additional purchases) of lenses.