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Full control. Choose your billing model: CPM, flat rate or bid. Select the number of Sponsored Comments per article, and whether those comments can include a link to another site. Set unique parameters for each section of your site (channels)
Sounds like you pay per impression or by click which would imply that the sponsored comment could vary each time the page loads (eg: if your budget has maxed out they can't keep showing your ad). Would the comment get indexed by google? If not then it would have no SEO value, but you might get some direct traffic.