How does the On Sale extension work?
On Sale adds additional attributes to each product, thereby allows defining different labels and specifying text of your products for catalog and product views. Both label image and text can be easily customized.
Moreover, labels can be assigned to different products according to created rules. When conditions of the rule are true, the rule is triggered and the rule-based labels appear in the frontend.
You can define label position, use variables in the text and run your promo campaigns being sure, that all your brand new products and discounts won't be passed over.