There are different forms to offering free shipping, but it truly makes a difference, you can do a customer segmentation of those who can wait and those who cannot, people that want 1-day delivery pay extra, while those who wait have free shipping. Another way is to include shipping costs in your product’s final price and not wait until checkout since an additional last-minute price can make your customer bounce off. Lastly, you could set a minimum order amount for free shipping, with this in mind, people will most likely try to purchase enough items to enjoy free shipping. Test, measure and improve what works best for your company.