Google has introduced Online Product Inventory Feeds that allows incremental updates to price, availability and/or sale prices for specific online offers.
This feed consists of an offer’s id, as well as the respective attributes (price, availability, sale_price + sale_price_effective_date) that online retailers would want updated. Online Product Inventory Feeds will be processed faster than full online Shopping product feeds (4x faster), and can also include only a subset of offers that need an update. Thus enabling fresher price and availability information in Google Shopping.
There are two main benefits:
1. Update speed: the regular product feed updates once per day. The new shopping feed updates instantaneously after processing.
2. Scalability: the new feed allows for updating of price/availability (plus sale price information) for all or a subset of items separately from updating the regular product feed.
Check out more about Online Product Inventory Feeds Here