To surpass (another) in an amount sold: a book that outsold all others of its kind. (verb-transitive)
To outdo (another) in selling: a salesperson who outsold her colleagues. (verb-transitive)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Use "outsell" in a sentence
"Will Obama, yes, we can cola in a bottle not a can despite the name outsell John McCain soda made with pure patriotic spirit."
"I understand they're updated hourly and with sales of a single copy can jump up thousands of places ... only to subside gradually as other titles outsell it during any given hour."
"As far as I know, fantasy in general still tends to outsell most other varieties of speculative fiction (there are exceptions, of course – individual sf writers who have sales many fantasy authors, including yours truly, can only dream of)."