K&FCONCEPT has two main deals running right now: the Back to School Sale with up to 50% off plus an extra 15% off sale products, and the 15th Anniversary & Prime Day promotion offering 15% off sitewide. Which one saves you the most depends on what you're buying and whether you're shopping sale items or full-price stock.
Shopping sale items at Back to School prices: The Back to School Sale is your best bet here. You'll get up to 50% off the sale selection first, then an additional 15% off those already discounted products. If you find items marked down 50% and then take a further 15% off that reduced price, the savings stack up quickly. For example, a $100 item at 50% off costs $50, and 15% off that brings it to $42.50—a total saving of $57.50.
Buying full-price products: The 15th Anniversary & Prime Day deal is your option here. Since it applies sitewide at 15% off, you'll save 15% on anything at regular price. The Back to School Sale won't help you if the products you want aren't in the sale section.
First-time shoppers: If you're new to K&FCONCEPT and want to stay in the loop with their offers, signing up to the newsletter will put you on the list for special promotions and deals going forward—a good move before you shop.
Only one offer can apply at checkout, so compare what's available in your basket. If you're buying sale items, calculate whether the stacked 50% plus 15% off saves more than if those same items were available at full price with 15% off—it almost certainly will. If you're shopping full-price products, the 15% sitewide discount is your straightforward choice.