The Association of American Publishers have released sales figures for ebooks.
“Trade book sales (not including books for academic study) for the period of January-August 2010 had sales of $2.91 billion. eBook sales in the same period were $263 million. E books for the period comprise 9.03% of total consumer book sales, compared to 3.31 percent at the close of 2009.”
“AAP’s more than 300 members include most of the major commercial publishers in the United States”.