The reasons for the incorrect allocation could be the following:
Your offer was allocated incorrectly because the categorisation in your feed is not conclusive/optimised.
Your offer was allocated incorrectly because a categorisation is missing in your feed.
The mapping of the offers needs to be improved on idealo's side.
To avoid incorrect allocations, please send us a meaningful categorisation in your feed for all offers. We recommend a "path" structure, such as: "Hardware > Hard Drives > 3.5 inch > S-ATA". In order for the internal allocation to work reliably, it is important that you give a product type. We kindly ask that you amend your feed accordingly.
Please contact us via the contact form in your idealo Business account, giving examples of affected offers.