* Reddit is a cesspit waiting to fail that encourages abuse as a platform. I am waiting for what replaces them as there is a lot of information people are looking to share without the torrent of garbage that comes with it currently.

* Slashdot faded because new buyers came in who didn't understand the product.

* RSS still exists and is going strong. It just does the job without the flash, the reason content producers don't like it is that you can't monetize it in the same way as email. I personally use TheOldReader for curating this.

* I'm going to add Sourceforge as a site that shot themselves in the face. It seems like it's newest owners have done a lot to try and repair the damage.

Raindrop looks fantastic, I'm glad you brought it up. I'm guessing we few are the kind of people keeping this type of service alive.