<Li> Cost per impression </Li> <Tr> <Th> Display advertising </Th> </Tr> <Tr> <Td> <Ul> <Li> Ad blocking </Li> <Li> Contextual advertising </Li> <Li> Behavioral targeting </Li> </Ul> </Td> </Tr> <Ul> <Li> Ad blocking </Li> <Li> Contextual advertising </Li> <Li> Behavioral targeting </Li> </Ul>

Which of the following is not a factor that affects the search process