1. A computer-implemented method of estimating one or more in-store transactions of one or more unknown users based on a correlation of an online browsing activity of at least one known user and at least one in-store transaction of the at least one known user within a predetermined period of time of the online browsing activity of the at least one known user, said computer implemented method, performed using one or more computer processors, comprising: (a) maintaining on one or more computers an online browser repository, the online browser repository having online browser activity data identifying online browser activity of a plurality of known users in connection with at least one online retail environment; (b) receiving in-store transactional data from an in-store retail environment for each of the plurality of known users, the in-store transactional data including data related to purchases of one or more products by each of the plurality of known users; (c) correlating, by the one or more computer processors, the in-store transactional data of at least one of the plurality of known users created prior and subsequent to the creation of the online browser activity data of the at least one of the plurality of known users to identify web-influenced in-store transactions for the at least one of the plurality of known users, (d) projecting, by the one or more computer processors, in-store transactions of at least one unknown user based on results of step (c).