Legal Question in Business Law in Maryland

So long as the articles and operating agreement or bylaws allow for it, yes, an existing business could open up multiple retail shops or sites even if they don't relate to the original business model. The law doesn't care too much if unrelated business endeavors are operated through a single entity so long as the entity is properly registered and complying with its own purpose clauses.

That being said, you may wish to have an attorney review your purpose clause and governing documents. Also, there are a host of things to be careful of when doing business online and any business should be careful to ensure that they register in any jurisdiction where they may be said to "do business" and should also take care to collect and remit applicable sales tax, etc. Those rules would apply regardless of whether commerce was operated through one or many different entities.