My aunt let me scan two obituary scrapbooks that my grandfather David D. Fast #112786 and great-aunt Minnie Fast #315950 (brother and sister) had kept. This is a great resource for a couple reasons.
First, they contain obituaries of people I'm interested in but haven't had the time to find - for example, their sister Margaret died at age 29, and I have always wondered why. Aunt Minnie pasted her obituary into her scrapbook, so I will translate it to see what the cause of death was. There are lots of other collateral ancestors whom I would never take the time to research, but the obituaries contain brief life histories of them.
Second, these scrapbooks add members to their FAN club (Friends, Associates, Neighbors) and to that of their parents (since they were collecting obituaries, many of them are from an older generation).
Here's a clip from Aunt Minnie's scrapbook:
I'm not going to write a formal source here because I don't want to put the name and residence of my aunt online for privacy reasons.