A little while ago, a user called /u/Maklo_Never_Forget had a problem: a stuck transaction. Maklo sensibly decided to ask /r/bitcoin about it, promising a $20 reward to anyone who could solve it.
I solved it: I explained what he could do, pointed him to the ViaBTC Transaction Accelerator, and sure enough the confirmations came pouring in, as he confirmed himself.
The response? The post was deleted and no payment made. Now, I don't need $20 – I'd be happy to see it go to charity instead – but I do believe quite firmly in paying one's debts. So, consider this a heads-up: if /u/Maklo_Never_Forget comes around with promises of rewards for assistance, he's lying.