Another good moment is also given by a case when a product line is getting close to the end and the company wishes to sell the remaining items. A price discount could thus encourage the client to but a product that is otherwise out of fashion.
On the other hand, advertising is useful when you are attempting to build a brand and the product is new on the market. The advertising could thus be used to promote the new product and provide the necessary information for its purchase.
Advertising is also useful when the product is new and innovative, so as to make it better known to the potential clients.
In general, it is useful to combine the two when you are advertising a sales promotion, usually also around the holiday period. At the same time, it is useful to combine them when the budget is large enough to allow such.