On the second day our team of 10 stayed together in a double paceline to chat and go at a relativly slow pace. Between the 13 mile rest stop and the second rest stop we somehow picked up closer to 40 riders (which looked awesome in double file). It is just part of it.
I have had people ask if they want me to pull and i always offer, but rarely announce my latching on to a paceline. I just assume people will notice (I look back a fair amount). also some teams rotate but want their team on front so only the front rotates and the suckers stya where they are which always stuck me as fine.