Upselling and cross-selling are proven techniques that can give you an immediate boost in sales. Especially with the drop-shipping model, when it costs you nothing to add additional correlating products to offer your customers. So basically, you can leverage these techniques at no risk. And Boost Sales is one of the best Shopify apps that helps to lift up conversions and sales by increasing order value per online shopper. Especially, it can automatically collect your sales data and generate offers which make customers more likely to purchase.