In most cases, link is not added by the user. It is the website admin which adds link to specific keywords like 'Best Buy' in this case. May be he is in tie up with some ad agency and so some words like Amazon, Best Buy, Vodafone..........as such are highlighted as links which will divert to a related website of the company.
So, normal members do not have the privilege to add a link i guess.
To Juan. Optical disc / writer technology hasn't change much in recent years. Mostly due to the abundant availability and affordability of flash memory and external hdds. You know, why burn CDs/DVDs when you can store multiple discs worth of data in a flash drive, which is even more compact and don't need to worry about coasters.
LightScribe was a small niche in the optical disc market invented by HP. There were better commercial CD label printers available, if one's aiming to make discs commercially. So really LightScribe was only aiming for general consumers wanting to etch labels onto their discs, one at a time. Because it's only a small audience and required to buy special discs designed for etching, it had never catch on fully in the market. It was discontinued last year and even the official LightScribe website's closed. http://lightscribe.com/
But... you can still find them, albeit they're rarer and more expensive. And I think LG is the only one left that still makes them.