See 2018 VIB Promotions.
Most Sephora promotions are online only. They are generally available with a $25-$50 purchase (depending on how great the promotion is). That is usually the only way to get pre-packaged samples as well, because you can select three free samples with every online purchase. There are rare times when Sephora has pre-packaged samples in stores and even less often when they have promotions in stores. Store promotions usually have the same rules as online promotion meaning a $35 online purchase would also require a $35 in-store purchase to redeem the promotion. Sephora released a promotion that requires a $35 purchase online, but it does not require a purchase in store. This is not even the first free in-store promotion this year.