This will be the first question in your mind for when you are considering to start/publish your business online. Here are simple and quick answers:
Reach of Internet: As you know internet is not bound to any boundaries, walls or borders, it is available everywhere (even on the remotest areas of the World now, thanks to companies and people dedicated to this… Internet.org by Facebook is playing vital role in making it available everywhere, read more about it on Wikipedia, also about Project Loon on this Wikipedia link), so if you go online you can easily attain better outreach for your business/brand.
24/7 Availability: Your business/virtual-showroom is available 24/7 with all of its products/services (along their availability), guidance, functionality (payment methods, receipt/email confirmation system etc.) so you can rely on it and stay connected with it via your computers, mobile phones and tablet pcs.
Limited budget will do: Unlike conventional/outbound marketing, that may cost more (for advertising on TV, Billboard, Print media etc.) this inbound strategy based online marketing is way too cheap and effective. As you are going to attract only the exact targeted audience, who are actually interested in your offered products or services (they can be in any phase of ‘buyer’s journey’, i.e. Awareness > Consideration > Evaluation > Decision).
Staying in touch: Internet provides ease of staying in touch with old customers (for announcing upcoming attractions, keeping them satisfied by providing quick online support, keeping the engaged via email, social media etc.) to make them your brand-evangelists.
In sum, internet, search engines, social networks, latest gadgets + IOT (Internet of Things) has completely revolutionized the businesses used to work till 90s or early 2000s, and in current times it is the most critical need of your business/brand to be available on Internet.