Jam is the one of the few things we've canned. (The only other thing is dilly beans.)
We like to make our own jam because it's one way to preserve our fruits and especially because we can make it much less sweet than most jams found in stores.
We've usually made about 5 dozen 12-oz jars, which gets us through the year with no problem. I'm not sure whether this is more or less than most people use in the course of the year, but we each have two pieces of peanut butter and jelly every day, and John often uses any that don't set up properly on his pancakes or waffles.
Our favorite pectin
We also used to add it to our plain yogurt, but since we've been making yogurt using Wake Robin Farm's milk, it has been so delicious plain that we haven't added any jam to it. We may be developing a surplus of jam, so perhaps we won't make as much from now on.
We use all of our blackberries, currants, and ground cherries for jam, and some of our grapes and raspberries.
We prefer Pomona pectin, which we have found gives consistently good results.
We have also used other pectins that allow us to use less sugar. We don't, however, use artificial sweetener, just a greatly reduced amount of regular cane sugar.