One of the differences between e-mail marketing and paid search is...?
Select one:
a. It is less expensive to use e-mail addresses than it is to use key words in paid search.
b. With e-mail marketing, you know in advance who will be receiving your message
c. All of these are differences between e-mail marketing and paid search.
d. With e-mail marketing, key words go in the subject line
e. With e-mail marketing you can direct customers directly to your website.