Methods sad apparatuses to select tracking mechanisms for the performance determination of advertisements. One embodiment includes: selecting one reference type from a plurality of reference types; and determining a reference of the selected type, the reference to be embedded in m advertisement, to count communication leads generated from the advertisement. In one embodiment, the advertisement is to be charged according to a performance measure based on communication leads generated from the advertisement. For example, a price for the advertisement cart be specified by a party for which the advertisement is to be presented. For example, the advertisement can be charged in response to a voice communication responding to the advertisement. In one embodiment, the plurality of reference types correspond to different mechanisms to track communication leads generated from the advertisement.