For awhile webmasters were stuck on buying paid links. But link networks have pretty much gone by the wayside and I think the reason why is because their business model has been destroyed.
Google has built a great system for detecting bogus links. There are tell-tale signs that a link is a paid-for link and not a natural link. For instance, if you have the perfect anchor text for “viagra” on a website about pet ownership, then there’s a clear indication that you have a bought link.
There are other signs as well. Link sellers generally spin their content. So if you find articles online with similar content over and over again with a mix of irrelevant anchor text links, that’s likely a link seller’s page. Google Panda took care of a lot of those.
And then the big kicker. Google operatives.
Imagine trying to sell links to an unsuspecting webmaster, but that webmaster turns out to be a Google employee. Bam! You’re dead.
It’s much like the way drug dealers and law enforcement personnel work. The dealer tries to find strung out peeps to sell his drugs to, but he has no way of weeding out the real fiends and those playacting. Law enforcement actually has an advantage. They work undercover pretending to be the type of customer the drug dealer wants. When an offer is made, bam! Snagged.
Google has its undercover agents as well, and they’re pretty good. If you’re still buying paid links, you’re throwing your money away. You’d be better off buying content the old-fashioned way and marketing through high quality content that builds your reputation and your SEO.