We have to be tough. We have to accept that domains, names, customers are not ours until they are ours. Blaming someone for doing what can be done is a weak position. If your sales are suffering it's because you are not calling your old customers and finding new ones.

My customers are only my customers if they are buying from me. If someone else sells them something or if my brand is easy to copy then my product and my sales are weak and need to get stronger.

That's free enterprise.