This has been asked in the past (e.g. Booster badge should be golden or easier to achieve ) but since that point a few patterns have developed which make the argument stronger.
The Nice/Good/Great questions and Popular/Notable/Famous questions and Nice/Good/Great answers badges have been awarded such that the bronze badge awards is an order of magnitude higher than the silver badge awards, which is an order of magnitude higher than the gold badge:
On the other hand, the number of questions that earned the booster badge but not the publicist badge seems low relative to the number of publicist badges (323 publicist, 828 booster).
Type Bronze Silver Gold
Question Score 1.39 E5 3.42 E4 4.1 E3
Question Views 1.1 E6 4.61 E5 8.8 E4
Answer Score 3.237 E5 7.63 E4 9.2 E3
..
Shared Link Views 1.7 E4 8.28 E2 3.23 E2
Should the threshold for booster be reduced to something like 200?