Ask HN: Recommend a recommendation system

I'm looking into the viability of using a recommendation system to add additional search results to a users' results list in cases where the search criteria may exclude results because that result does not have up to date data.

For example, searching for hotel rooms within a certain price bracket for a certain period and we don't have price and availability data for the period in question.

It would use previous searches by all users to show that if your results contain X,Y and Z, it's likely that result A and B would also be of interest. e.g. Previous searches where price and availability data was present.

I would think it'd work in a similar fashion to a regular recommendation engine for a shop or news site - if you read / bought these, try these.

Currently a Django / Postgresql / Elasticsearch based site