Building an online store is crucial for any business looking to expand its reach and increase sales. When it comes to choosing the best place to start, there are three main options: building your own website, selling on an established online marketplace like Amazon or eBay, and focusing on social media as a primary channel. Each option has its pros and cons, with built-in traffic, advertising options, logistical services, and seller communities being advantages of selling on online marketplaces, while control over design, making one's own rules, and no extra fees are benefits of building one's own eCommerce site. On the other hand, social media selling offers access to people researching products, built-in traffic, faster conversions, and an easier way to find target audiences, but it also comes with limitations such as only working on certain platforms and inhibiting certain marketing strategies. Ultimately, the best choice depends on a business's goals, target customers, personal strengths, and logistical issues, requiring careful consideration of each option before making a decision.