Which online channels have you found to be the valuable in terms of ROI of web marketing dollars? If necessary, talk about how it may have been different for each of the industries in which you've worked.
Your interviewer will ask you a variety of questions that will require you to speak to your experience while flexing your industry knowledge, so be prepared to provide specific examples covering a range of topics. This question in particular requires additional contextual understanding, so be sure to provide context in your response to help the interviewer better understand your valuation process. The second part of this question should be a hint to you that different channels might be more valuable in different contexts and industries.
"My answer to this question definitely depends on the circumstances of the project or campaign. Generally, I have found that SEO is a great foundation for our more veteran products while email marketing and pay-per-click often serve our newly released products better."