1. A computer-implemented method comprising: determining, by a computing system, whether a candidate content item may be presented in response to an indication of approval by a user regarding a seed content item according to a first technique, wherein the seed content item is a seed page and the candidate content item is a candidate page; determining, by the computing system, whether the seed content item may be presented in response to an indication of approval by the user regarding the candidate content item according to a second technique; and processing, by the computing system, features, including a reciprocity feature based on the determining whether a candidate content item may be presented and the determining whether the seed content item may be presented, to generate a probability that the user will interact with the candidate content item.