the long sell
A scheme, trick or a practical joke that may take days, weeks and sometimes years to accomplish. Usually done with bad intentions. Very few people have the unimaginable self discipline that it takes to perpetuate this ongoing charade.
In "there's something about Mary," the long sell pulled off by Norm, the pizza delivery guy is quite impressive. By pretending to have a broken back and using crutches day in and day out he is able to get up close and personal with her as his chiropractor. The count of Monte cristo holds the record for the longest sell in history...20 years.