Google’s Matt Cutts has been making light of paid links all week, but in reality, Google isn’t joking when it comes to enforcing this part of its quality guidelines. According to Google, it’s cracking down on this more than ever, and we have seen in recent weeks, that Google is indeed cracking down.

Now, the serious stuff.

Cutts participated in a keynote discussion at SMX Advanced, and while much of the talk was about Penguin, the subject of paid links also came up. SMX sister site Search Engine Land has a liveblogged account of the discussion. Here’s what Cutts said about paid links, according to that:

We’re always working on improving our tools. Some of the tools that we built, for example, to spot blog networks, can also be used to spot link buying. People sometimes think they can buy links without a footprint, but you don’t know about the person on the other side. People need to realize that, as we build up new tools, paid links becomes a higher risk endeavor. We’ve said it for years, but we’re starting to enforce it more.

It makes you wonder how safe those directories that charge for “reviews” to potentially get links are.

The liveblog continues:

I believe, if you ask any SEO, is SEO harder now than 5-6 years ago, I think they’d say it’s a little more challenging. You can expect that to increase. Google is getting more serious about buying and selling links. Penguin showed that some stuff that may work short term won’t work in the long term.

On a semi-related note, Cutts also talked about paid inclusion, given that this has been in the news, as it relates to Google’s new sponsored results and Google Shopping.

“You call it paid inclusion, but it’s a separately labeled box and it’s not in web ranking,” Cutts told Danny Sullivan, according to the liveblog, which continues: “Google’s take on paid inclusion is when you take money and don’t disclose it. Google’s web rankings remain just as pure as they were 10 years ago. We have more stuff around the edges, that’s true, but that stuff is helpful. Matt mentions using Google Flight Search to book his trip here to Seattle. ‘You can’t buy higher rankings. That hasn’t changed. I don’t expect it to change.'”

At the conference, Cutts also revealed that Google is considering launching a tool that would allow webmasters to tell Google to ignore certain links. The idea is already attracting a lot of praise from webmasters, many of which though Google should have had something like this long ago. Cutts indicated that such a tool would be several months away.