Google Analytics is a smart tool for measuring your online performance. Here are some key metrics you should look at on a regular basis:

Number of sessions

A session is a group of interactions a user takes within a given time frame. Google defines this time frame as 30 minutes.

A Unique Visitor = New User

Visits = Sessions

All of the actions a user takes while on your website is considered 1 session. Whereas a unique visitor or new user is how many times that individual goes to your website in the same browser without clearing cache or cookies.

Screen Shot 2015-07-10 at 1.12.03 PMNew visitors vs. returning visitors

You want new visitors and returning visitors.

New visitors become aware of your service for the first time, you can answer their questions during this initial stage and they return when they are ready to move forward with contacting your company.

Most users that arrive on a website for the first time are: researching, looking for options, or looking for alternatives. They are typically not ready to speak with someone.

Having a good ratio of new and returning visitors is a good thing. Returning visitors are most likely to get in contact with you.

Number of sessions by medium

Screen Shot 2015-07-10 at 1.12.09 PMThis is the number of sessions by source: organic, referral, social media or direct traffic.

The mix of traffic will vary for many different reasons. Large companies will generally have 50% of its online traffic generated from direct results (ie: a user typing in the web address).

It’s important to know what channels are producing the most amount of web traffic. This won’t tell you exactly what channels are performing the best (ie: converting into inquiries), but it will show what channels have the largest opportunity for growth.

Bounce rate

Screen Shot 2015-07-10 at 1.12.17 PM The Bounce Rate, as defined by Google Analytics, is the number of people entering a page and exiting from that same page.

Average bounce rate should be 40-50%. If there is a channel that has a higher than usual bounce rate it could be because that channel is not acquiring the right type of user. As long as the bounce rate overall stays on average relatively low you are ok.

Average Session duration

The Average Session Duration metric is calculated by dividing the total amount of time visitors spend on your site by the total number of Sessions.

A good benchmark for session duration is 1-3 minutes. If your website has a lower session duration it could mean that there is not enough information to keep the user there or it could mean that it’s just really efficient at providing the user with just enough information he/she needs. I know, a total curveball! The best way to think about this is by industry and your business. It’s logical to assume that the more complex the product or service, the more time a user should be on your site digesting information.
source: http://www.business2community.com/online-marketing/important-metrics-in-google-analytics-01273455#tzvYiLm83pYfUuDu.99