Read all Trilogy MBTI -Persönlichkeitstyp
Persönlichkeit
"Welcher Persönlichkeitstyp ist {profilename}? {profilename} ist ein {MBTI} -Persönlichkeitstyp in MBTI, {enneagram} - {iv} - {tritype} in EnneArgram, {big5} in Big 5, {socionics} in Socionics."
ISTJs I know will always finish a trilogy as long as they have started it. Everyone with high Si or Te will be likely to complete them. ENTPs on the contrary, are likely to give up after the first book.
Biografie
Read all three books in a trilogy. Even if the sequels are bad, because they liked the first book they will finish all. (by user @[pk725])