'Are you happy? If not, consult Mr. Parker Pyne, 17 Richmond Street.' Just a simple advertisement in the personals column that directs people to Parker Pyne's office. Those that answer the ad are greeted by the efficient Miss Lemon (later to become Poirot's secretary), led into Mr. Pyne's office and then reveal their troubles - boredom, spousal infidelities, theft or just general discontent for Mr. Pyne and staff to sort out.

Reuploaded Thanks to pancracy