Google wants content on your site to help it understand what your value proposition is to the Internet in general. The more value your website has, the greater ranking you will have.
If you have products only on your site then Google is going to want to display other websites ahead of yours that they feel will offer users a better experience, more content, and as far as Google is concerned they have just done the best thing for the user.
It doesn't matter if you have the best customer service, the best widgets, even the best prices if you are not going to come to the top of the rankings it will be hard for customers to get your better experience.
I would suggest writing a list of your greatest value propositions to the customer and writing an article on each explaining them and giving more details and testimonials. Same thing for each of your products, why is that product the best, what do your customers think, and what are some ways your customers can use your products? The more articles you can write (500 words or more) the more Google will like your site and the higher you will go in the rankings. Getting a better organic ranking will save you money on Google Adwords, the articles will have more keywords and key-phrases bringing in new customers that found you on long-tail searches, and the benefit is forever because this one-time effort brings in long term results.