It always did until the AIA law went into effect. Now the law says:
" PRIOR ART.—A person shall be entitled to a patent unless—
(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention;"
If the italicized phrase modifies "public use or in sale" the the world has changed and confidential transactions would not start the clock. If it is a catch all for anything that is not a public use or on sale then the world hasn't changed. It will take future court cases to really know.
Also there is a judicially created exception for "experiment use". Beta testing could fall under this. The inventor needs to retain control, collect data, etc. But it must be an experiment to see if the invention works, not if people like it or if there is a new feature wanted or to iron out tiny bugs. The classic example was the new street paving formulation (in the 1800's). The inventor thought his new road paving system would last two years with normal traffic. He got paid to have a section of roadway paved. It was clearly in the public and in use and even for commercial gain. But it dreamed the experimental use exception because he didn't have another way to see if it would really last two years.