I'm going to chime in here with another voice in support of perpetual versions. In your current business schema you've overlooked the needs of many of your customers: specifically, contractors. I am one of them, and it just isn't practical for me to sign onto an annual subscription when next year's clients may want all ILT or Lectora. What happens then, when I've been working on another type of project entirely for 8 months and a previous client asks for a "quick fix" to something in SL? At that point I can't even access something that is part of my own portfolio! Quite a lot of your customers are contractors like myself, and you've put us in a bind.