Many deceiving e-mails can be found in the internet that offer you nothing essential at all. Read one of the occasions that claim to offer the ability to advertise in Google with the purchase of an extra domain name for an already existing website.

We have in our possession the domain (domain name) domainname.gr and we can transfer the name to you with only 160 euro for life! Why is it worth buying: the certain domain name will help you gain higher places in Google and more visitors in your website from key word searches: (something close to the domain name). We make it clear that this domain name was registered legally from us 2 years ago. Your website address will be : www.domainname.gr

Which is the reality though? It is that having a second name for your website will not help you at all, because when Google sees the same content in two different names, just undervalues and eliminates the second one from searches.

When there are more than two names in the same website, Google thinks it is deception and may degrade the full content of your website.
If you want to increase your visitors with more than one domain names, you must create a website for each domain name, with different content from one another, in which you will create links to your main website for more. This is the correct way to gain from different domain names in search engines.