For voice over actors, it is a race to the bottom of the pay scale. Two competing brands may say you have a conflict of interest. If you work for one company, the other may not higher you. Also, voice over actors carve out a niche which is hard to break into in order to make anything. Finally, you have to put out your own money for equipment such as private coaching, building a web site, making demos, having a professional mic and pre-amp and a sound proof recording space that has the right acoustics. which cuts into your income.