There are many questions that come in asking how to "make it" when the voiceover field is so competitive. There are lots of stories of people trying and not succeeding.
What is the key? What is the secret? The secret is to never, ever give up and to always keep trying different approaches. It is a mistake to try the same approach or market when it is not producing results. The voiceover industry is not just about talking. Certain voices have traits that work much better in certain voiceovers. None of us can do everything. It takes endless experimentation to find the copy and the areas where we can do our best work and where people will respond by hiring us.
One has to be a crazy insane scientist to discover one's personal path to success and greater skills. Sometimes people want to just focus on the approach they have always used, perhaps because of moderate success. The reality is the voiceover business is always changing pretty dramatically and we have to change and reinvent with it or be left out. It can be done, you can succeed. It takes imagination, tremendous persistence, and skill. Turn on the media and notice that the good, the bad and the ugly are all working...so why not you:)