If you struggle with knitting, prefer loom knitting versus needles, or you can crochet and have not sucessfully learned knitting, buy this! I personaly am much more comfortable with a hook and the knook allows me to have my cake and eat it too.
First and foremost this type of knitting has a wonderful drape to it that you will not find in traditional knitting methods and it works in a way that is very comfortable for weavers and crocheters.
What you are basically doing is casting on as if you were about to start Tunesian Crochet. Then you simply knit each stitch individually along the cord attached to the hook in much the same way as traditional knitting. The only differences being that you are using a crochet hook instead of a knitting needle, and that your stitches will be picked up along the crochet hook and the attached cord.
At the end of each row you push the knitting down off the hook and onto the cord - there should now be two rows of cord in your knitting. The next step is to pull the bottom portion of the cord out of the knitting and not move the top portion of the cord or else you will loose the stitches you just knit hence unraveling your work. Turn your work over and start your next row as if you were going to crochet with the cord in front of your yarn. This way you are knitting and not purling.
If you have had your stitches fall off the cord then your cord is too short and you need a longer piece of it. Preferably I like to have 12 inches of cord hang along the left side of my work (I'm right handed). I found out the hard way that if I don't give myself 12 inches that I will run out of cord before I finish my row and loose my stitches.
When I couldn't see my stitches it was because they were too tight, and I wasn't using a big enough crochet hook. (I'm really lucky that I have relatives who knit and crochet that straightened me out on this.) They told me to pull the cord straight and then dig my hook into the loop going directly over the cord, complete that row and then switch to a bigger hook.
Don't worry about dropping stitches. It's much easier to fix your mistakes with this then with traditional knitting. If you drop a stitch you just pick it back up on the next row. If you decide to take your work off the cord and rip out the mistake, when you're done you just thread the cord into a needle and run it back through the loops. -- This product is a big plus for klutzy knitters. I love it.