I did a report writing course a couple of years ago. The crux is that all important info needs to be in the first paragraph. Following paragraphs can then drill into the detail. This means lazy readers get the important stuff right at the beginning.
In other words, Cakewalk's marketing info needs to state very clearly in the first few sentences that
you own Sonar forever if (a) you pay outright for a year, or (b) you complete 12 consecutive payments. Basically, many people read the first few sentences and think they know everything, but assume the detail. You can't leave important stuff till later in the document (or web page).
Personally, I think Cakewalk/Gibson needs to jump on this quick, because once wrong info is circulated in the public domain, it takes 10 times the effort to correct it than it would to have got it right in the first place.
Just my $0.02c
EDIT:Hmm, just took a look and it's pretty darn clear when you click "Membership" on Cakewalk's site:
Pay Upfront:
Just like before, you can purchase SONAR with a one-time payment and immediately own a permanent license.