A courier is supposed to approach me after i come out of the house after killing greload the kind.
No one approaches me when i exit the building. Nothing happens even if i wait a few days and go sleep in a random inn as mentioned by the wiki as well.
Pretty sure it had to be midnight, so wait until 11:40pm then wait till midnight somewhere out on a road. I almost missed it because i jumped in water and he nearly decided to walk away.
if you still hadn't solve it, i suggest you stop waiting and do other side quests. i read your post and it discouraged me from waiting, and whadya know, the courier found me in whiterun after i got back from kiting a mammoth for ysolda(not that it matters, just wanna gloat that i killed a mammoth.. and only died twice)
Here's what I did. I didn't wait at all, I remembered that in Oblivion you had to kill an innocent person and go to bed in any bed and the Dark Brotherhood would find you.
So, I took the mission from the boy to kill the old woman at the Orphanage and I found a bed and went to sleep and woke up somewhere else with someone from the Dark Brotherhood there.
i have actualy just done this.. i was in another city and did the killing of the old crone for the young lad, so i left the city and went to another location @NIGHT time'' and a courier just come and given me the mysterious note.. ei: Dark brotherhood.
--------------------------------------------------------------------------- Drem. Patience.There are formalities that must be observed, at the first meeting of two of the dov. By long tradition, the elder speaks first. Hear my Thu'um! Feel it in your bones. Match it, if you are Dovahkiin!