The article here covers the essentials regarding Nosto and SEO.

First of all, if you are at all worried about SEO, first thing to review is that you are using canonical meta tag on your site, including your product pages. If you don’t, please consider adding it as described in the next chapter.

In case your site doesn’t make use of canonical url tags, we suggest to add them right away. These will not only prevent Nosto’s parameters to appear on Google search results, but also use of canonical urls should dramatically improves your SEO in general.

In short, the canonical url defines what is the preferred url of the page for search engines and a common SEO practice since 2012.

Effectively search engines and web-crawlers will ignore any parameter or link on the Internet, added by any service or web-site, and treat the url in the canonical url tag as the primary url of the page, preventing the same page from appearing multiple times in the search results. As a general advise, use the same canonical url in your social plug-ins for example in Facebook’s like button if one is applied.

There are also other ways to make sure Google does not index URLs with Nosto parameters – and thus avoid duplicate content – however canonical url is the most important one.

1) Specify Canonical URLs in in the head section of the page

2) This is the most robust method as it covers not only Google, but all search engines. and strips away possible parameters. Read also Moz’s blog entry on the topic.

3) Specify how Google should handle parameters in Google

4) Specify Nosto links as “nofollow” in the templates. Learn more about "nofollow" links here.

Albeit an alt attribute of an image is slightly controversial regarding SEO, it’s covered as an FAQ in this article.

The alt-attribute in the recommendation templates is by default left empty by Nosto, because we don’t want to determine on behalf of you which product attribute should be used as a value for the alt-attribute. When using Nosto’s default templates, the alt-value is as below.

In case you prefer having a product name as an alt attribute of an image tag, simply edit the recommendation template and return the preferred value. In the example below, a product name is used.

Google and every other search engine generally treats the site positively if a page has a valuable internal link structure that connects and groups similar content together. A recommender system such as Nosto, when set up correctly, will show highly relevant context that is related to page, product and category viewed.

According to latest studies, albeit not officially confirmed, Googlebot seems to be able to follow and crawl links in elements, which are populated in-site using Javascript. This means that product recommendations by Nosto will create automatically internal linking structure between your products, possibly boosting SEO. As this has not been officially confirmed, please treat this note with a grain of salt.

Landing page recommendation is a recommendation type that optimises product selection offered to a customer landing on the site from a paid ad. It automates the showing of relevant product recommendations based on the keyword bought by you. This will update according to the user behavior after landing on the page with that keyword and of course self-optimize. Read more here.

In Nosto’s context, duplicate content is not the case. Duplicate content typically refers that the same page or content exists elsewhere on the Internet or on the same site, consequently meaning that search engines have hard time to figure out which one of the pages is the most relevant. See first chapter about canonical urls covering duplicate pages.

When it comes to page content and not duplicate pages, Nosto does repeat some content in the product page tagging (product attributes), however the tagging is hidden and not visible to people visiting your site, hence it’s treated differently than visible content by search engines. An example snippet of product page tagging below:

Nosto doesn’t use user agent cloaking. We treat all requests the same, irrespective of whether they come from bots or individuals.

Hidden text and link-misconception is the most common argument regarding Nosto tagging and unarguably without understanding the context and functionality of the tagging that Nosto applies, it can be perceived as a keyword spam by SEO specialists.

Hidden content often refers to bad practices and attempts to improve site’s SEO and search ranking by populating visible content, which is in practice hidden. Such content and attempt is a violation of for example Google’s webmaster guidelines as it is true that hiding (with display:none or by other means) information from the end user is considered a big NO in SEO circles.

The aim of the hidden and “SEO-poisonous” content is to manipulate search engine rankings, but we have to remember that Google has gotten really smart when it comes to determining the use of hidden content. Google can tell the difference between legitimate hidden content and black hat hidden content. Google even executes JavaScript now to some extent. So if you’re hiding content for Black Hat reasons, it’s bad. If you’re hiding content for layout, form or other convenient reasons such as for applying Nosto’s tagging it shouldn’t have any negative implications to Google. In the end, it’s all a question of context and that is something Google has worked really hard to understand properly.
When it comes to Nosto, hidden content is used for appropriate reasons and not to game Search Engine Rankings. Therefore we consider Nosto tagging to follow the current Webmaster Guidelines and be safe for all websites.

Nosto’s content is hidden using a style-property, effectively meaning that the content of the element is not visible for the eye, yet search engine crawlers will analyse the content in hidden elements. Nevertheless, as referred previously there are many different and legitimate uses for hidden content and sites are not automatically penalized if this is used accordingly and in a way it doesn’t look spammy for search engine algorithms.

Nosto’s tagging simply repeats values that are already present and visible on the page as product attributes, hence these are not treated as spammy hidden content according to current webmaster guidelines. In addition, the size of the tagging is very small.

As an eloquent example, if you would map hundreds of popular keywords for all your products in the Nosto tagging such as “Ferrari”, “Viagra”, “Amazon” and so on, this would surely be treated as a guideline violation and would cause penalising your site by the search engines, but as long as the attributes are relevant and integral part of the product and technically the product page itself, applying Nosto tagging as a hidden content on product detail pages doesn’t cause SEO penalization.

Google uses page load times as one of the factors how they rank pages in search so adequate page load time is taken into account when Google ranks pages in its service. To Google user experience especially on mobile is important, hence while adequate page load time and generally acceptable target of two seconds is a good rule of thumb to follow. Thus, site speed is one of the factor that Google looks into and if the site is loading really slowly, it will have a negative impact on user experience, which might lead to penalization.

Google assesses page loads by “full page load”, which takes into account also services and elements that are loaded asynchronously and possibly from third parties such as from Nosto. When assessing page load times in conjunction with Nosto always take into consideration that as Nosto’s elements start loading recommendations once the DOMContentLoaded (DOM)event happens.
On most websites, the DOM-event happens early enough to load the recommendations in time so that they seem to be a part of page’s native elements hence the user experience is not affected. In many cases, Nosto effectively pends until DOM takes place, before injecting the content to the site. Therefore an increased load time and possible penalization can be caused by sites own, synchronous scripts. Read more about page load times and optimization here.

All elements on the site effectively increase page load times as more data needs to be transmitted over the Internet from a server to a client. To ensure that service response time is fast and impact to page load times minimal, Nosto uses Amazon’s CloudFront CDN while service response time is almost always below 30ms, meaning that response and content load times are extremely fast considering that the content shown to users is personalized and different to all website visitors. If the same content that Nosto serves would be loaded from the site’s own servers, the load time and impact on search engine rankings might be more severe.

As a good guideline, one should track more how user experience is improved or impaired by adding more elements from a service like Nosto and by tracking is the root cause of possible increased page load time in site’s own content before DOM.