An upsell seems to have happened on my GIG-GRU-IAD flight on 3/30. WAs in 17B and there were 3 others in the middle section of that row. One lady was trying to bring a friend up from E- and was told she could not by an FA. She tried with another with no success. Then just before push back, an FA moved two people into the empty seats in that row. The other couple voiced the fact to the FA that they had paid for E+ and were wondering why these people were moved there. The FA responded that they had paid for the upsell. Not sure whether it was paid for on board.