Online Marketing coveres more than only advertisment, I will get back to that later on, for now I will emphasize paid advertisment, so that you as a company owner, who might be active on facebook or instagram etcetera, might see the benefits of it.

• Exposure.
  When you advertise your company, you obviesly try to create attention to your business in the hope it leads to selling your products or service(s). This should make sense to the most readers, if not everybody.
  Some might not even have to expose them self online, if they only are cable of selling locally to a minor customer group because of lower supply and demand. 
  I think this is also important to consider, if you do get attention, if you are able to keep up, so that you don’t constantly disappoint all the time, and possible instead get a bad rep. 
  Then you can probably imagine it the other way around, that you are more than cable of keeping up!?
• Branding.
  A lot of us knows a lot of brands, even ones we might not even really shop, but useally, because bigger companies have com up with a catsy melodi or slogan in their advertisment. It could of course also just be popular without any catsy melodi or phrase, but then maybe because of quality. 
  But branding your business, just useally requiers exposure, and with higher demand and if supply follows, therefor advertisment.
• Target groups.
  With paid advertisment online, you can narrow your advertisment down to only reach your target group or groups, a little more precise, than when doing advertisment through tv commercials or the radio. Unless you a big enough of a company, surely they use all channels avialable, but will also spent a lot of unnecessary money. 
  If you are an smaller or new started business, you are proably not interrested in spending money unnecessary, even though it might feel like that sometimes anyway. 
  Well, this is where upscaling or finetuning your advertisment online, comes in, and can potential change how much you get in return for you money, in short also refered to as ROI.
• Testing.
  Paid advertisment online, also give you the option to do test, and see if your ideally target group actually also matches with the more broad group of your buyers. If not, then you have the chance to redirect your advertisment more towards that group that actually represent the broader group of your costumers.
• Leads.
  Looking for new leads? You might have a business that provide a service or services. In this case I can use my own line of work as an example, but I will also just mention a couple of other examples. 
  You might offer to repair something specific, maybe even looking for new students for next years start of school or education. As a real estate company, you might be looking for sellers, and buyers, of property. You could also just want to sell something within niche.
  You might be an attorney looking for new clients.
  As of my own line of work, I can do a campaign regarding leads to filter out the ones who might show interest but dosn’t act upon my offers and those who does, without committing though. This gives you the oppourtunity to have a list of potential clients that you then later on can follow up on by contacting them, because you would useally ask permission to do so, so that you don’t bother people who dosn’t want to be contacted by someone who are just trying to sell them something.
  This list useally comes in the form of an opt-in, that gives people the option to willingly give up some sort of contact information.
• Campaigns.
  Want new followers to your facebook business profil? Then you could also use paid advertisment to create campaigns that is about anything other then trying to sell something and give discount out right and left, and instead lure new people to follow your page by creating something of interest. 
  Of course it is useally something in the line of a competition, where people can win something or get a discount. Before you do that, remember to read about the rules concerning gifts and competitions, and maybe also try and come up with something else more creative, but also tempting. 
  Then of course you have the useally seasonally sales or something similar, that many do campaigns about.