As this topic rears it's ugly head, let's stir it up and punch down any mistaken impressions.
You can make many really yummy foods with sourdough starter (banana split bread to name the most important one in my mind). It is quite often referred to as FRIENDSHIP bread, the Amish are well known for it. You bake a loaf of bread with the "starter" -a yeast mix that you nurture into being- and then you give a loaf of the bread along with a cup of starter that you then nurture and pass on by the cup.
Many a person has been hornswoggled by someone professing to be a "friend" with this method. Google likens it to a chain letter. It is a post office gone BAD PEOPLE! TERRIBLY, TERRIBLY BAD!
It starts out innocently enough (or so it appears) - you get a yummy loaf of bread and some delicious yeast starter that you feed and put in your refrigerator, You wait a couple of days take a cup out make some bread and feed him again. You wait a couple more days, make another loaf of bread (this time for the neighbor along with a cup of starter because by now the starter has doubled in size. So you feed him again, wait a couple of days , make your favorite board President some Sourdough Pretzels which she loves and give her a cup of her own starter. You feed yours again and then you name him. He's become a bit of a pet now. A member of the family. I named him Seymour, for obvious reasons. Another couple of days pass and it's time to feed Seymour again after you make another decadent treat (or two) and pass another (2) cups on to a (EACH) "friend"..and then you go on vacation for a week or get distracted by work or your life and oops..Seymour has had an accident in your refrigerator.. poor little guy.. you feel awful throwing away the overflow, it's like discarding puppies, but it can't be helped, and you make 4 things this time before you feed him because you feel so bad for the loss.
Space is limited so let me summarize. You feed him twice in the next week, you single handedly put on the entire bake sale for the library fundraiser, YOU offer to PAY for the baked items for people with the only stipulation being that they take a couple of cups of starter home with each sourdough item they take. Gifts abound. People buy it for their co-workers, their families. What a GREAT idea. The gift that keeps on growing. After the bake sale I moved from the state, abandoned my home (THE BLOB had overrun the first two floors by then) and I got into the witness protection program. Because the quickest way I know to ever end a friendship is to innocently give a "friend" a loaf of "friendship" bread and a cup of terror...
For those that don't believe this account, try it yourself...