What are the blue dots?
Discussion
non standard transactions that were not accepted or relayed by default mempools
floodgates are opening
The blue I think specifies that those transactions were not seen in the mempool before being added to the block, meaning the miner added them manually. Looks like most of them are non standard transactions too.
Do miners add them to improve their take-home fees?
Yes.
Yeah exactly, its all about the financial gain really. Those blue transactions are likely paying a premium, and are occurring out of the mempool.
To see a block that full of transactions that were never seen on the mempool is a bit disconcerting to me, as it means fee prediction can't be accurate, and the large miners are getting a further advantage over small miners because people go straight to them with these special transactions.
Its one of the reasons to remove the OP_RETURN limit... but I don't know where I stand on it yet. still need to research a bit more.