How to make huge profit in domain name trading?

The usual (and legitimate) way of making money out of domain name trading is to buy domain names which are related to a particular topic, use them in building a good website which relates to the topic and generates traffic and to then sell the website (and the domain name associated with it) as a 'going concern'. In other words, what you are selling is the value you have added to the domain name by ensuring that it is listed well in search engines. There is another way of speculating in domain names which is barely legitimate or ethical and, in some cases, is illegal. That is to simply search for and buy (if possible) any names which might be useful or relevant to large and successful concerns and to then try to sell them at a profit to those organisations without doing anything more. To give a very banal example, if a well-known company has a .com address but has not already bought up other, similar, top-level domain names, one might try to buy the .info, .co.uk and .org versions of the name in the hope that they will be prepared to buy them off you for a profit. In practice, this is unlikely to work and you could find yourself sued for misrepresentation under Trading Names laws.