During 3L, BarBri heavily heavily recruits students for their summer bar prep course. As part of the spamming, they invite you to put down a $25 deposit (or fill out an "I'm interested!" card or something similar).
Once you pay the nominal deposit or sign your name on a sheet, you have free access to BarBri's MPRE materials and their lecture course. IIRC, it was a few hours long and you could attend multiple times if you felt like it.