This update doesn't change anything, really, it just reverses the effect; before, you were paying SEO black-hats to create links to your site, which should result in elevating your search rank, but now, you will be paying SEO black-hats to create links to competitors' sites, sinking them in the search results, and relatively elevating your search rank.
The only thing search engines can do to stop SEO spam is to avoid giving any weight to spammy links.
Suppose that the natural situation, with no SEO at all, is that you have the #1 site on some keyword, and your competitor has a lower ranking.
With "positive" SEO, okay, your competitor might have paid a lot of money and bumped you to the #2 site, and that might be frustrating -- but you're still #2!
With "negative" SEO, your competitor pays a lot of money and now you're #100. And that sucks more for you.
Probably not important in the really big keywords where all the top sites have always paid big money for SEO -- then, sure, it's all just relative. But in the relative backwaters where lots of sites aren't engaging in SEO at all, having negative techniques work is a lot more frustrating to the people who just don't want to play the game.
> The only thing search engines can do to stop SEO spam is to avoid giving any weight to spammy links.
That didn't work before. Zero weight for spammy links is gamed by spammers by spamming everything at full blast. There was no downside for them. There are better dials and switches than falling back to a known broken model.
With penalties in place spammers need to get those existing bad links removed for their own sites / or build from scratch new sites with clean link profiles (which they are doing anyway, slash and burn). Now they will need to multiply their efforts to negatively target sites above them (not just rank one site, but unrank several sites). Good luck doing that without leaving a detectable fingerprint/trace.
The history of when links are created - that will leave a clear beacon that a site has been targeted. Unless a spammer does it very slowly over the course of years. In which case, LOL.
Don't you think it would be noticeable that a site ranking well, with a clean back link profile suddenly starts attracting heaps and heaps of bad spammy links? That's a clear indication something is going on.
The better time to use negative SEO is when the spammer has already gotten ahead of his competitor. Then the influx of bad links might look like an effort to regain rankings. That would be more interesting.
As mentioned in the article, that works if you can identify every spammy link. Without a penalty, you can make a million spammy links, let the filter catch 95% of them, and reap the benefits from the ones that get past.
That system isn't exploitable to sabotage another site's rank, but it also doesn't work at preventing link farms (as evidenced by most Google results before the recent change).
It doesnt take a genius to realize that when you identified 1 million bad links to XXX, and your database has 1.005 links to XXX, you should look carefully at the remaining 5K. Cross reference those sources against other suspicious links and so on.
Basically fight source of bad links, not recipients.
Google, lets stop pretending we are talking about any other search engines, will learn in time to identify and penalize source of spammy links instead of recipients. Webmasters should be responsible only for the content they have control over.
The disavow tool is a step in that direction. But frankly, I suspect the only people that are using it are the blackhat SEOs and their customers trying to undo the damage hey caused, the rest of the world does not even realize it exists.
The only thing search engines can do to stop SEO spam is to avoid giving any weight to spammy links.