Abstract: An online system maintains information describing user interactions with advertisements and other content. Additionally, the online system maintains various types of information identifying users and confidence values associated with each type of information identifying users that provide a measure of the likelihood of a type of information identifying a specific user. Example types of information identifying a user include an online system identifier, a client device identifier, and an application identifier. When the online system receives information indicating a user has performed a conversion, the online system retrieves interactions associated with at least one type of information identifying the user. An attribution model is applied to the retrieved interactions to determine contributions of various interactions to the conversion, accounting for the confidence values associated with types of information identifying the user associated with various interactions.

Abstract: Approaches are described for automatically generating new security credentials, such as security tokens, which can involve automatically re-authenticating a user (or client device) using a previous security token issued to that user (or device). The re-authentication can happen without any knowledge and/or action on the part of the user. The re-authentication mechanism can invalidate and/or keep track of the previous security token, such that when a subsequent request is received that includes the previous security token, the new security token can be invalidated, and the user caused to re-authenticate, as receiving more than one request with the previous security token can be indicative that the user's token might have been stolen.

Abstract: Approaches are described for automatically generating new security credentials, such as security tokens, which can involve automatically re-authenticating a user (or client device) using a previous security token issued to that user (or device). The re-authentication can happen without any knowledge and/or action on the part of the user. The re-authentication mechanism can invalidate and/or keep track of the previous security token, such that when a subsequent request is received that includes the previous security token, the new security token can be invalidated, and the user caused to re-authenticate, as receiving more than one request with the previous security token can be indicative that the user's token might have been stolen.