That is how to make personalized content-based recommendations.You’d have to input content by attaching it to items and recording it separately as a usage event per content bit. The input , for instance would be every term in the description of an item the user purchased. The input would be huge and the current UR + PIO is not optimized for that kind of input. It is not a recommended mode to use the UR and is of dubious value without NLP techniques such as word2vec or NER instead of bag-of-word type content. It might be ok if you have rich metadata like categories or tags.
In general content based recommendations are often little better than some filtering of popular or rotating promoted items (with no purchase history), both can be done fairly easily with the UR.
Content based with NLP techniques for short lived items like news can work well but require extra phases in from of the recommender to do the NLP.