So, the mystery has to do with visitors to my shop and shop hearts. I check Craftcult several times a day to see my shop hearts. I know that hearts don't equal sales, but I think of it as a general barometer of how appealing my shop is. And really, it just makes me feel good. It's a bit of harmless affirmation.
Last night, the number jumped. It jumped so much that I thought it was a glitch and wondered if Craftcult was having problems. There was more than a page of new hearts. That is not typical for my shop! So I went to Craftopolis to see if it also had the anomalous hearts.

Look at the visitors, views and hearts for Aug 9. 821 unique visitors, 2611 page views, and 44 new shop hearts. I was gobsmacked. And I still thought it might be a glitch.
Keep in mind that in May a skein of my yarn was in an Etsy front page Treasury. That day I netted 300+ unique visitors and 26 shop hearts. This blew that day away.
I was still skeptical so I checked and everything kept saying it was real, so I started hunting for the source. I googled my shop, I checked for any more front page treasuries, I checked treasuries in general, I checked Ravelry, I even checked Etsy finds on the slim chance. I came up blank everywhere. There was nothing to explain why people had suddenly decided to heart my shop right and left starting 8:48pm last night.
I waited for midnight so I could check my analytics, and there was the completely unexpected source. Facebook.