Amazon gives non-Prime members free shipping at $35 or more of eligible items. Instead of simply letting users get the product with free shipping, they’ve added a discount that prices it exactly one cent below the $35 limit, while only subsidizing the price with $3.38, which is about half of what they’ll then charge you for shipping.
Unless you buy useless stuff just to avoid shipping, it’s still money spent toward something you would have bought later (possibly for a higher price, on retail). It counts on future savings.