Link popularity is used to describe the amount of web sites that are linked to a given web site. For those of you who are new to this idea, the higher link popularity that you have, the higher ranking you will have on search engines.
Google is one of the more renowned search engines known for using link popularity, and they see each link to your web site as a "vote". Some votes are more potent than others do to their individual PageRank and the relevance it has to your web site.
There are many quick fix gimmicks out there including Link Farms, FFA's and Link programs. They might temporarily boost your rankings, but once the search engines realize what you are doing they will most likely demote your rankings or ban your web site all together. There is only one way that I find acceptable to boost your link popularity on perpose, earn it. Find web sites that are related to yours and are good quality, ask the web master if they would link to your web site (often they will ask for a return link), and wait for a response.
While there is a lot of controversy as to what exactly is taken into consideration, what I suggest is not to worry about the total number of inbound links that you have, but rather the quality of the inbound links. Quality inbound links will not only boost your web site ranking in search engines, but will also boost your traffic directly from the link itself. Google and many other search engines are using a combination of quantity, quality, and relevance to decide link popularity.
The disadvantage that comes with link popularity depends solely on the size of your organization. Large organizations have a huge advantage over smaller organizations. One of the examples that I see being used more and more is Pizza Hut.
Pizza Hut randomly gives away a free pizza to web sites that link to them. Because of this search engines that count link popularity tend to rank Pizza Hut #1 for the keyword 'pizza' even though their web site contains very little text content.
The ideal situation to gaining traffic through link popularity is to have quality web sites that are relevant to your web site link to you on the grounds that they are doing so because they feal your web site is superior and has alot to offer.
This is often a lot harder then you might imagine, but should be a long term goal for everyone that is looking to succeed with link popularity.