The criteria and metrics can be classified according to its type and time span. Regarding the type, we can either evaluate these campaigns "Quantitatively" or "Qualitatively". Quantitative metrics may include "Sales Volume" and "Revenue Increase/Decrease". While qualitative metrics may include the enhanced "Brand awareness, image and health" as well as the "relationship with the customers".
Online marketing is the practice of leveraging web-based channels to spread a message about a company’s brand, products, or services to its potential customers. The methods and techniques used for online marketing include email, social media, display advertising, search engine optimization, and more. The objective of marketing is to reach potential customers through the channels where they spend time reading, searching, shopping, or socializing online.

However, with all of these so-called modern conveniences to life, where technology's ever-pervading presence has improved even the most basic tasks for us such as hailing a ride or ordering food or conducting any sort of commerce instantly and efficiently, many are left in the dark. While all of us have become self-professed experts at consuming content and utilizing a variety of tools freely available to search and seek out information, we're effectively drowning in a sea of digital overload.
The biggest problem that most people have when trying to learn anything to do with driving more traffic to their website or boosting their visibility across a variety of online mediums, is that they try to do the least amount of work for the greatest return. They cut corners and they take shortcuts. Because of that, they fail. Today, if you're serious about marketing anything on the web, you have to gain Google's trust.
Trust is the foundation of conversions and sales. But building trust should be a goal on its own. The whole concept of content marketing is based on trust and creating long-term relationships. Stop selling and let the people come to you by providing them interesting and useful information. I couldn’t have said it better than Mark Schaefer, the Executive Director of Schaefer Marketing Solutions:

Next, place the fill light at a 45-degree angle on the other side and lift it close to or just above eye level. The purpose of the fill is to soften the shadows created by the key, but without getting rid of them completely. Therefore, the fill should be dimmer than the key light. If you have to use the same type of light for both, scoot the fill back and diffuse it by clipping a clear shower curtain onto the clamp light with clothes pins.