The relative values of the Deluxe, Standard, and Economy depends on the total population of tutors, the specificity of students' searches, and the predilection of students to pick the first tutor listed over the second, third, etc. If the population of tutors is very large and the students do low-specificity searches, then they will get very long lists of candidates. Under such conditions, Deluxe level tutors will dominate the first pages and the relative value of the ad will track the number of cards given (i.e., 10:3:1). If, on the other hand, there is a very small number of total tutors or the students use very specific searches, then the number of tutors returned by a search may be very small. With a small number of candidates, tutors of all ad levels will make the first page of hits and only the tendency of the student to take the top of the list will determine the relative value.You might try doing a search to see how many tutors are similar to you. If the number seems large, then spring for the deluxe level. If your searches show that you're competing with only a few tutors, then buy the economy ad. I suppose there may be a set of conditions in which the standard ad is optimal, but I'd bet it's a very small window in the parameter space.