Revenue in the U.S. self-storage industry will climb past $30 billion in 2018 and will approach $33 billion two years later, according to a new forecast from market research company IBISWorld. IBISWorld predicts self-storage revenue will grow at an average annual rate of 2.9 percent through 2020. “Over the next five years, the industry will continue to reap the benefits of an improving economy,” according to the forecast, obtained by The SpareFoot Storage Beat.