The rule is that an online agreement constitutes an offer as long as a reasonable website visitor would be on notice that they are being invited to enter a contractual relationship under the terms accessible via a hyperlink.
The terms of use was not visible when a user was looking at the button which the user had to click to download SmartDownload. The user had to scroll down through several screens to find the hyperlink to the Terms of Use agreement.
Specht is sometimes interpreted as holding that the Terms of Use agreement was not offer because it was not visible when clicking on the download button.
By analogy, agreements involved in the offline purchase of goods would also not be offers when the agreement was include in the box the product came in and not accessible until after purchase.