学割(gakuwari) "student discount" is common but it seems offering an original discount ○○割 is quite popular recently.
I went out to look for posters of a number of different discount and took pictures!
学割(gakuwari) student discount is a standard discount for mobile companies now.
乗り換え割(norikae wari) "transfer discount" is another popular discount.
"If you will switch to our company from another company, we will give you a discount."
平日割(heijitsu wari) "weekdays discount" if for people who use their service on weekdays not weekends.
まとめ割(matome wari) "putting together discount" is same as パック割(pakku wari).
学生家族いっしょ割(gakusei kazoku issho wari) "student and family together discount" by Docomo and 家族の学割(kazoku no gakuwari) "family's student discount" by Softbank is that not only students, but also the students' family will get a discount.
If you buy an item with someone else like your family, friends, boyfriend or girlfriend, you will get a discount.
What kind of discount have you gotten?
I think there are more different types of discount. If you find any, let me know please!