Upon installing the software, he was presented with a notice on his computer screen describing the license agreement, which in turn required clicking a checkbox to show consent.

[2] The district court ruled that the buyer of a software package is not required to observe a shrinkwrap license because in this case, the message on the outside of the CD-ROM box (under the shrink wrap) only served as a notice that there was a contractual agreement inside, and did not constitute an enforceable contract in itself.

The circuit court held that while the message on the outside of the CD-ROM package was merely a notification of the full contract to be found inside, this did not force a purchase as Zeidenberg claimed.

The circuit court also held that Zeidenberg then had ample opportunity to review the license after opening the package, and indicated his acceptance of the agreement by clicking the relevant checkbox before he could begin using the SelectPhone software.

[1] Finally, the circuit court held that a shrinkwrap license, when used for a product that can be returned if the buyer disagrees with the larger agreement inside the package, constitutes a valid and enforceable contract.

[1] The Seventh Circuit's ruling in ProCD, Inc. v. Zeidenberg was praised by the corporate community for confirming the applicability and enforceability of shrinkwrap licenses, which had been a rising trend at the time but without settled law.

[7][8] The ruling also received some criticism, in agreement with Zeidenberg's argument, that ProCD intended to use contract law to indirectly enforce control over un-copyrightable facts such as phone numbers.