This is Rae from Shopify. Thanks for posting this question about your domain, and how this will impact sales on your site.
It's absolutely possible to use your .myshopify.com URL as the primary domain on your site while making sales. However, there are also many benefits of using a custom domain name, and many reasons for why this is recommended, too. With that said, are you hoping to use your .myshopify.com URL, rather than a custom domain?
If so, it's important to mention that using a custom domain can really improve the branding on your site. When building your brand, the purpose is to create a unique look, feel, voice, tone, and personality. With this in mind, a large part of your company's brand is its name, so it's essential to use a domain that reflects this. We have a great blog post that discusses more information on branding - and how domains are involved with this process - right here.
Custom domains are also great for customer recognition, as consumers are more likely to recall a custom domain name, and in turn, find the associated website quickly and easily. I suggest checking out our store launch checklist for more details on this. Additionally, if you decide to re-name your store, or use a different name than you originally selected in your .myshopify.com URL, using a custom domain with your new store name is a great way to ensure this new name is displayed to your customers, rather than your old name. We've shared more details on this in our step-by-step guide for setting up a new Shopify store.
These factors can all help create brand credibility, too. This is essential for all businesses, as it's important for customers to have trust in your product, website, and company, as well as know that they're buying from a credible business. I recommend checking out this podcast to learn more about how a specific business used to a domain to build credibility in their brand, as well as drive traffic to their site, and ultimately increase sales.
I'd really like to hear more about your fashion line, and the brand you're building, so that we can discuss your domain and your business plans further. Do you already have a business name selected?
I hope to hear back from you soon!