Google has introduced a new feature in the toolbar called the Sidewiki. Users can post and read comments about any website that appear on a pane on the left hand side of their browser. An example showing this is presented below.
You can use a Firefox or Internet Explorer browser both of which are compatible with the Google toolbar. You also need a Gmail account with which your comments can be associated.
The sidewiki panel that appears on a website will be displayed to users with the toolbar installed. It is a separate window that appears to the left of your browser. All the comments displayed are stored on Google servers.
This annotation of the web through the sidwiki pane on any website is not owned by a site owner. It is activated by a program that users install on their computers of their own volition.
The disconcerting fact is that when visitors arrive at your site by either typing in your website address or clicking a link that points to your site, they can see comments on the side of your site.
There is no separate URL on the sidewiki panel that shows the source of the comments. They look like part of your site. It cannot be taken for granted that all users know the concept behind sidewiki even if they have willingly installed it on their computers. The comments beside your site can lead to users assuming that it is part of your site.
Unlike your blog on your site where you can moderate the comments, in the case of sidewiki, as the site owner, you have no control over the comments that appear beside your site.
The Google moderation team will ensure that damaging comments will be prevented from getting published. But there is no guarantee on this. As Matt Cutts always states, it is the intent which Google has a close look at (behind any strategy or move by webmasters). In this case, it may not be truly relevant as malicious competitors can hold the key to the comments and the site owner cannot do anything about it.
If visitors to your site were to see offensive comments on the sidewiki panel that fly under the moderation team’s radar, it can reflect badly on your site and can stop repeat visits after that experience.
Consider the example where you search on Google for the term “sidewiki controversy” (without the quotes). Have a look at the second result on the Google SERPs in the screenshot below.
The link below the second SERP result clearly shows the Google domain as the URL. On clicking the link, you are taken to a wikipedia page titled Vaccine Controversy. You can see that the comment on the Sidewiki panel has been indexed by Google and displayed on the Google SERPS. The highlighted portion on the screenshot below (click to enlarge the image) matches the second result on the Google SERPs in the screenshot above this.
If sidewiki comments can influence search engine rankings, then that is a matter of worry too as your competitors can leverage it to their advantage by posting comments that are contextual to the content on your site and get your site ranked for search terms with negative intent.
Google might possibly consider the aspect of monetizing the comments made on sidewiki panel through contextual advertisements in future. These can confound the web landscape further as ads placed can be contextual to the comments made that in turn corroborate with the content of the site on which the sidewiki panel is displayed.
With commercial sites selling products or services, an ad with an affiliate link in direct competition to the site on whose left side it is displayed can become a classic case of riding piggyback on some site owner’s hard work.
I am certain Google will take precautions to counter these possible ill effects. Maybe an idea would be to exclude websites with commercial intent from this sidewiki feature to start with. Once the system is ascertained to be foolproof in the non commercial space, then it can be slowly introduced to include commercial sites.