Assuming no physical storefront, in terms of branding, which is a better name; "Website Name" or "WebsiteName.com"?
It is same like this mylyapp and when user search myly look the results. "WebsiteName.com" is a Domain Name but for Branding USE "Website Name". How? In the title <title>Website Name | some keywords ... </title>
"Website Name" would be better if the name of your website includes the keywords you would like to rank for and you're using actual text that the search engines will pick up.
In terms of branding its "Website Name" would do while for the domain websitename.com Your target keyword along with your brand name.
I think you should use "WebsiteName.com" as a main domain, with "Website Name" is the main brand and main keyword.