For example, if the phisher is attempting to emulate PayPal, there are so many previous attempts made to phish PayPal that anything that is extremely close to PayPal social website URL is either already a registered domain, or is blacklisted.
in order for a phisher to emulate a Paypal URL, they have to start introducing misspellings, such as www.paypal.com, or they must construct another domain name to look like PayPal, such as www.paypal.com.anotherurl.com.