CPA (Cost Per Action or Cost Per Acquisition) or PPP (Pay Per Performance) advertising means the advertiser pays for the number of users who perform a desired activity, such as completing a purchase or filling out a registration form. Performance-based compensation can also incorporate revenue sharing, where publishers earn a percentage of the advertiser's profits made as a result of the ad. Performance-based compensation shifts the risk of failed advertising onto publishers.:4, 16
The first known large-scale non-commercial spam message was sent on 18 January 1994 by an Andrews University system administrator, by cross-posting a religious message to all USENET newsgroups. In January 1994 Mark Eberra started the first email marketing company for opt in email list under the domain Insideconnect.com. He also started the Direct Email Marketing Association to help stop unwanted email and prevent spam.  
Market researchers usually have at least a bachelor’s degree in market research, statistics, sociology or other related field. Some researchers, particularly those with companies dedicated to market research and in larger corporations, have a master’s degree. Market researchers who take advantage of internships, either during or immediately after college, will also gain valuable hands-on experience they can use in the future.
Project conversion metrics. The general rule of thumb is that the smaller and more targeted your list, the more you can spend per piece. It’s better to make a strong impression to a few than to make a weak impression to many. Know your cost per unit, and project a conversion rate, so you can estimate whether your campaign will have a positive ROI before running it.
Cost per mille, often abbreviated to CPM, means that advertisers pay for every thousand displays of their message to potential customers (mille is the Latin word for thousand). In the online context, ad displays are usually called "impressions." Definitions of an "impression" vary among publishers, and some impressions may not be charged because they don't represent a new exposure to an actual customer. Advertisers can use technologies such as web bugs to verify if an impression is actually delivered.:59
Email marketing has been around for decades, but it is still one of the most effective digital marketing channels available when it’s done well. Email today needs to feel like one-on-one conversations with each audience member, but it also needs to scale. Make sure your strategies are up-to-date so your emails are getting delivered and cutting through the noise.