Not sure on this, not an expert, but buying a round surely is not just buying goodwill. You can never guarantee a customer will move over to you, so buying customers does not sound right. They can't be bought.
What you are buying is a database of contacts. Would this be tangible ? I read many businesses buying and selling databases, and sometimes these are worth a fortune.
They are potential customers and so aren't an asset. A customer is never an asset.
If none of the customers on the database you paid a fortune for bought anything from you, then the database is worthless. This is why they try to add value to a database - to make it more appealing but targeting a type of customer that would be more likely to buy the product or services being advertised.
Sir Peter Vardy once run the third biggest motor dealership in the country before he sold out to Evan Halshaw. Whenever he was approached by a manufacturer to take over a failing outlet, (Vauxhall in Leeds was one example), he would only buy the assets of that company, buildings, land, etc and a limited number of spare parts still in stock in the parts department. He wouldn't buy any customer database as he never bought goodwill.
He would make a really low offer, a take it or leave it type of thing.
However, when he sold the organisation to EH as a thriving business concern which was economically viable, then his customer database was worth something. How the tax side of it played out I'm afraid I do not know.