Well with all the mergers crushing smaller companies, it's more important than ever to find independent clients rather than relying on big casting sites or voiceover talent agencies. If you have an agent and that works for you, that's great!
We all need to be aware however that market forces are pushing rates down in general and the big mergers add to the pressure. There are many clients who do not use VO talent agencies or online casting web sites. Those are the majority of my corporate clients and it provides a certain amount of insulation from everything that's going on. look for areas where you can form a personal relationship with people who need voiceovers/narrations and take great care of them at a reasonable price.