What Are Backlinks? What Are Backlink Schemes?
Backlinks are links to your website from other websites.
When you see something interesting online you might post a link to it on your Twitter or Facebook account. This is natural and happens all the time. Likewise, other people might link to your website if it has good content or they find it interesting.
When search engines see many links pointing to the same website they assume that site has lots of value, otherwise people wouldn't be linking to it. There's more to it, but that's the theory. Backlinks are one of several hundred website quality factors, and sites with more links generally rank higher in searches than sites with fewer.
Enter The Scammers: Paid Links
Backlink (or "link building") schemes take advantage of a loophole in this aspect of evaluating website quality. Scammers falsely inflate the popularity of a site by selling hundreds (or thousands) of links to it. The loophole is that it may take several weeks for search engines to realize the links are worthless, and you really can get a ranking boost during that time, before they discover the abuse. Backlink schemes are one of the favorite tricks of black hat web designers.
So backlink schemes (or plans, systems, etc.) offer paid links to your website. For example, someone might offer you 200 backlinks for $249. This could be a one-time cost but is more often a monthly fee. Either way, they aren't naturally occurring, realistic, or logical links (you'd be shocked by some of the places they put backlinks). They typically stop working within 30 to 60 days and any mistaken boost in ranking from the crappy links will be reversed, and your site possibly deleted from search databases. At the very least you'll be penalized for trying to scam the search engines, and you may as well abandon the site and build a new one.
"The danger is simple: search engines know these are fake links, and you will be caught, it's just a matter of when."
This paid backlink abuse is ideal for con artists, because they can trick consumers into thinking a site is legitimate, sell a ton of stuff fast, then disappear. (Be very cautious of all search results!) It's pointless, dangerous, and counter-productive for real businesses who simply need a normal website that will stay highly ranked because it has genuine quality and credibility.
Avoid these linking scams at all costs, but do add your website to reputable local business directories, especially ones catering to your industry.