If you’re not familiar with link networks, don’t worry: That’s most likely a good thing. It means any links you’re using to improve the SEO on your site are legitimate and relevant.

While not every big link network is the same, the vast majority of these networks exist simply to provide one-stop shopping for links that include the kinds of keywords you want your site to rank for. The idea is that you deal with one provider, pay one price, and immediately get hundreds of seemingly relevant links to your site.

Here’s the problem: The very reason sites employ link networks is to improve their rankings, because Google (and other search providers) consider incoming links a good reason to rank a site highly.

But Google wants sites to grow their incoming links organically. That’s what tells Google that a site is highly relevant to what people are looking for. It knows you’re not necessarily relevant — that is, other sites aren’t linking to you simply because you’re useful — just because you have a mass of paid-for links.

Google’s Webmaster Guidelines warn against the use of link schemes. They specifically advise not to use “automated programs or services to create links to your site.”

However, lots of sites have chosen to ignore this admonition until there were some consequences. Now there are consequences, as Google has dropped a hammer on a ton of link networks.

On May 14th, Google took aggressive action against thousands of link networks, effectively rendering the vast majority of links included in those networks useless. It’s a big reminder that if you try to build links through an automated process, Google will find out.

To improve your SEO appropriately, build your links legitimately. Build incoming links by creating a blog that provides useful information about your industry. Invite guest posts that will attract links. Focus on quality over quantity with incoming directory links.

That will ensure solid SEO for your site now and in the future — with no nasty plummets in between.