I used the keywords "internet marketing" in MERLOT and found 63 results which include textbooks as well as assignments and textbook companions. This is the link to my search: https://www.merlot.org/merlot/materials.htm?keywords=internet+marketing&sort.property=relevance&btn_0=Search
While the search "internet marketing" yielded 0 results, I browsed their category of "marketing" and there are more than a dozen marketing textbooks, which can be found here: https://open.umn.edu/opentextbooks/subjects/marketing
