Parallels Support (via Mike Ash):
We use in-product notifications to share several types of information with our customers. First, and most importantly, we share information about product updates which are generally related to compatibility with OS X, new features and product enhancements. Second, we occasionally share special offers from Parallels or other third party companies who provide special deals for our customers. Many of our customers rely on the information about product updates and appreciate the special deals for products that are of interest to them.
Individual notifications can be turned off by clicking the “don’t show this again” button. However, because customers need to receive important product information, there is not a mechanism for customers to completely disable notifications.
The whole thread is disturbing. When Parallels first came out, I used it to run Windows. Lately, I’ve been using VMware Fusion, mostly to run prior and pre-release versions of Mac OS X — via Michael Tsai