Make sure your site complies with accessibility standards so your users can find and use the site properly. You may have digital marketing (SEO / PPC / SMO, etc., etc) to drive the traffic to your nopCommerce site but if the site is unusable then you may have wasted time and money as well as loss a potential lead/client.
There are industry and ISO standards to follow for web accessibility (Google: WCAG 2.0 and ISO / IEC 40500 for more information). Plus relevant legislation in your area - so if you are in America look for references in Section 508 and new ADA proposed changes.
Accessibility can't be covered by just one area - e.g. developers may use tools to check the site but it is more than just automated testing. It's also about manual testing, disabled user testing, policy and process reviews, and so on.
- Language is also key to the content, plain clear English
- Learning disabilities and difficulties (not the same thing) - which are dyslexia keep things short and to the point.
- Design for people with dementia
- Mobile devices like smartphones and tablets
Most accessibility audits can recommend improvements to usability and SEO.
Ask yourself, what happens if a disabled user contacts you to report they are struggling to use the web site?
What do you do? What processes do you have in place?
Just because you have access to open source software doesn't mean it cover all the bases. Eventually there will be some collaboration work needed.
Doing accessibility is an investment in the future and says a lot of you and your business.
Hope this helps.