CPC (Cost Per Click) or PPC (Pay per click) means advertisers pay each time a user clicks on the ad. CPC advertising works well when advertisers want visitors to their sites, but it's a less accurate measurement for advertisers looking to build brand awareness.[63] CPC's market share has grown each year since its introduction, eclipsing CPM to dominate two-thirds of all online advertising compensation methods.[24]:18[62]:1
The first is just common sense. Do you really think that hundreds of random people will be interested in what you are promoting? Probably not. Most will instantly delete the email, unsubscribe, or mark your email as spam. Plus, if you buy the list from a company that gathered the names in less-than-ethical ways, you risk being labeled a spammer. And if that happens, having a small database is the least of your worries.
If you’re serious about growing your business, building a healthy email list should be one of your top priorities. When it comes down to it, your list is one of the only online assets that you have 100% control over. Having a solid social media presence is absolutely essential (here’s why), but you’ll always be at the mercy of new and changing algorithms (think Facebook’s Edgerank). And achieving high search engine rankings is great too, but again, you’re at the mercy of changing algorithms and updates.

Particular groups of customers can be targeted or even individuals. Offering individual customers special deals on merchandise and/or services on the customer's birthday, for instance, is one example of email marketing personalization. (A restaurant might send an email to customers on their birthday offering 50% off an entree,) Email marketing helps a business develop and maintain a relationship with a customer over time that hopefully results in increased sales and increased customer loyalty. 

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