Usually companies with a low effective tax rate have lost money in recent years. This is especially true over the last 3 years (I believe 3 years is the limit on a carry-forward loss credit, and 2008-2011 has been bad for business). The net effect is that US companies pay 35% taxes on their 3-year trailing average income rather than income in a given year.
Occasionally you will hear another breathless claim on places like reddit/The Huffington Post/The Daily Kos that some large percent of corporations pay no corporate taxes at all. They are usually counting the large number of small businesses organized as S-corps and LLCs which pay pass-through personal income taxes rather than corporate taxes, and counting all the C-corps that lost money and therefore paid no corporate taxes for the year. On its face it is a true statement that most corporations pay no taxes, but it is a very misleading statement.
In my experience, it is very difficult for the shareholders of a C-corp in the United States to derive benefit from the entity's business activities without the benefits being taxed at the corporate level.
