Most of the time people use it for studying. With a particular lesson in mind. Otherwise consider your purpose. In what area would you like to see this improvement in memory. Remembering names? Remembering Faces? Remembering certain facts when reading?
If you just use it without anything in particular in mind... How will you know when you get there? You may have a razor sharp memory over time but it will seem as if you've "always" had a good menmory for "that" and you can wind up thinking the Paraliminal didn't help and that would put a block up for using the Paraliminal.
The Paraliminals do open the gates for the skills you always had so there are no significant feelings or roadsigns that anything has changed. By having a purpose before listening you're giving yourself a snap shot of where you are now.
If you don't have a propose why bother to listen? Why not listen to Prosperity? There is a reason why you want to listen to the Memory Supercharger. Somewhere along the line you are saying, 'I would like to improve my memory." So in what way, what would tell you that your memory has improved? How do you see yourself using your improved memory? Just noticing that gives you your snapshot of why you are listening to Memory Supercharger and there you have your purpose.
Yesterday I listened to Prosperity, my only purpose was, 'it would me nice to see some more cash flow towards me'. Not a grandious purpose but enough of a reason for me to put the CD on. Today someone put some cash into my account (unexpected). Enough to notice with amusement that it happened so soon after listening to the Prosperity CD with such a fluffy purpose last night.
Had I not noticed my purpose for listening I might have missed the connection 
Alex
