Online advertising helps you reach thousands of potential customers online each and every day which is impossible if done physically. To replicate this physically, we will require thousands of banners, hundreds of people and several weeks of planning and months to achieve. The cost will be 100 times less with online advertising.
As a business owner, you can display your ads on the Internet almost everywhere. You can pay the social media sites (such as Facebook, Instagram, Twitter etc), different blogs, news websites, YouTube and search engines (such as Google and Yahoo) to do so.
With Online advertising, you have the control on how much you want to spend each month or day and whom you wish to target (of course, on the basis of their age, gender, location, need etc).
The best thing about online advertising is its reporting capabilities. You can track spending on each advertisement each day on every website and its ROI.
Time Required: Around a week to set up and a couple of days to see the results.
Requisite: A website with a calling button or Lead capturing form (or Landing pages that have everything).
Reward: Once you know which platform (Google, Facebook, Twitter etc) works best for you. You have to keep running those ads. This will get your brand more reach, more visitors, more leads and ultimately more sales.