BACKGROUND Tobacco cessation among Latinos is a public health priority in the United States, particularly given the relatively high growth of this population segment. Although a substantial percentage of American Latinos use the Internet, they have not engaged in Web-based cessation programs as readily as other racial/ethnic subgroups. A lack of culturally specific advertising efforts may partl...

There are m positions to be allocated among n bidders, where n > m. We assume that the (expected) click-through rate of bidder i in position j is of the form αiγj , i.e. separable into an advertiser effect αi ∈ [0, 1] and position effect γj ∈ [0, 1]. We assume that γ1 > γ2 > . . . > γk > 0 and let γj = 0 for j > k. We will sometimes refer to αi as the relevance of bidder i. It is useful to inte...

A web user \clicks through" one web site, the referrer, to another web site, the target, if the user follows a hypertext link to the target's site contained in a web page served from the referrer's site. Numerous click-through payment programs have been established on the web, by which (the webmaster of) a target site pays a referrer site for each click through that referrer to the target. Howe...

Figure 1. Bats regulate biosonar sampling based on the availability of vision. (A) Naïve bats’ click rate (left Y-axis, mean ± s.e., black line) and click intensity (right Y-axis, mean ± s.e., gray line). The averages were calculated across all individuals for each of the light levels (B) On-board audio recordings of echolocation in the laboratory under different light levels. X and Y scale bar...

Search advertising is the ordered list of advertisements that appears when a user searches for something in an online search engine. By construction, these ads differ in prominence: ads higher up the list are more prominent than ads lower down the list. However, search ads also differ in prominence in another way: prominence of advertiser. This paper examines how these two types of prominence i...

We consider the problem of estimating occurrence rates of rare events for extremely sparse data using pre-existing hierarchies and selected features to perform inference along multiple dimensions. In particular, we focus on the problem of estimating click rates for {Advertiser, Publisher, User} tuples where both the Advertisers and the Publishers are organized as hierarchies that capture broad ...

Sponsored search advertising offers a more targeted way of marketing than traditional advertising. However, the context of consumer search is often unobserved and the prediction of it can be nontrivial. Consumer search contexts may vary even when consumers are searching for the same keyword. Due to the ambiguity of a keyword, a large portion of the ads displayed may fall outside a particular co...

assess changes in auscultatory findings produced by pacing-induced variations in cardiac rate, rhythm, and conduction. As the heart rate was increased in stepwise intervals to the maximum possible extent by right atrial pacing (RAP) in 14 patients, the interval between the Q wave and the click (Q-C) decreased in all cases (21 ± 2 msec/10 beats/min; P < 0.001). In two patients, RAP at rates of a...