Google has made a subtle, but noteworthy change to its help center article on link schemes, which is part of its quality guidelines dissuading webmasters from engaging in spammy SEO tactics.
Google put out a video last summer about adding rel="nofollow" to links that are included in widgets:
In that, Matt Cutts, Google's head of webspam, said, “I would not rely on widgets and infographics as your primary way to gather links, and I would recommend putting a nofollow, especially on widgets, because most people when they just copy and paste a segment of code, they don’t realize what all is going with that, and it’s usually not as much of an editorial choice because they might not see the links that are embedded in that widget."
“Depending on the scale of the stuff that you’re doing with infographics, you might consider putting a rel nofollow on infographic links as well,” he continued. “The value of those things might be branding. They might be to drive traffic. They might be to sort of let people know that your site or your service exists, but I wouldn’t expect a link from a widget to necessarily carry the same weight as an editorial link freely given where someone is recommending something and talking about it in a blog post. That sort of thing.”
In Google's guidance for link schemes, it gives "common examples of unnatural links that may violate our guidelines."
It used to include: "Links embedded in widgets that are distributed across various sites."
As Search Engine Land brings to our attention, that part now reads: "Keyword-rich, hidden or low-quality links embedded in widgets that are distributed across various sites."
That's a little more specific, and seems to indicate that the previous guidance cast a broader net over such links than what Google really frowns upon. That's worth noting.
You'd do well to pay attention to what Google thinks about link schemes, as the search engine has made a big point of cracking down on them lately (even if some have gotten off lightly).