It’s been demonstrated that quality outbound links from your website have a positive impact in Google rankings. If you’re big enough to link to other sites, search engines see that as a sign of being helpful to those trying to learn about a subject, and give you credit for it.
Google claims that outbound links are not a ranking factor but then says they could increase page quality. This would make the page more relevant for a search, and therefore make it rank higher. In other words, outbound links do make a difference.
There are a couple of types of pages where you might want to do more outbound linking. The first is the purely reference page, explaining a subject for no obvious commercial benefit. Do you have any pages like this? If not, you should certainly consider creating some. They might not generate sales, but they’ll generate inbound links and subsequent SEO advantages which will spread across your site. Technical concepts not already covered well online (e.g. on Wikipedia) are what you’re looking for.
As you’re not looking for sales from these pages, there’s no harm in adding outbound links. Indeed, if the outbound links are to non-commercial sites, you’re giving readers an alternative to returning to Google and possibly seeing your competitors there. Typical links might be to Wikipedia (to explain general concepts) or supporting research (for more in-depth analysis). Use Google Scholar to help with these.
The second type of page where you might consider outbound links is the ‘information hub’ which I’ve described in the past: the often-neglected page about ‘widgets’ which indexes all the various types of widget on your site. This is your ideal chance to create an authority page about widgets.
Now, you might be thinking that’s the last page where you want to introduce outbound links, just when your visitors are about to choose one of your product pages. But if your links are to research which backs up what you’re offering, anyone you ‘lose’ probably wasn’t poised to buy or enquire and will probably return. I think that the SEO benefits are more than a decent tradeoff.