For website owners that embed widgets within their sites, or those who distribute widgets, Google strongly recommends using nofollow attributes inside the widget link code, as a best practice.
Widgets are a common place of SEO abuse, and Google has taken notice. There are exceptions however. Originally Google recommended that all links within widgets should be a nofollow, but now the search giant is updating their recommendation to specify the types of links within widgets.
Specifically Google is referencing these types of links:
Links embedded in widgets that are distributed across various sites.
The specifications in Google Webmaster Tools warns against: links that are keyword rich, hidden or low-quality.
Thx to @dannysullivan for pointing out that we could clarify our stance on links embedded in widgets: https://t.co/038YpFwyPj
— Matt Cutts (@mattcutts) January 10, 2014
This abuse of widgets and link-building by distributing widgets with keyword-rich or low quality links. Google is taking a special interest in widgets that carry links. The best types of links to gain are editorial or freely given links from related and relevant websites.
A special concern for start-ups and small businesses
We feel that this is a considerable concern for small business or start-up marketing, where there may be a lot of pressure to make sudden and rapid traffic gains, but there may also be a lack of marketing or SEO experience present within the supporting team. Start-ups commonly push the boundaries of what is appropriate for marketing--making mistakes along the way that can harm their reputation or search ranking.
Google has been focusing heavily on discouraging spammers and link networks--along with those who employ their services to gain an advantage in search. Google recently penalized another link network, the “private link network” Anglo Rank. Additionally, Google appears to be set to punish hundreds of bloggers that use bribes to win favor for links and SEO favors. Certainly the pressure to succeed is extraordinary for many businesses, but some decisions can cost more than the inherent gains.