A bit late to the party, but there are some glaring oversights in this article which need to be addressed.
A patent protects an idea, technique or process, not a product. I do not think any of the SparkFun products would be 100% protected by patented aspects of those products. You are confusing patents with intellectual property protection, namely copyright.
As pointed out, the IP investment in each product is small – I’d guess under $1000 in any one. Thus a competitor would save a maximum of that amount by copying rather than designing. Also, it makes no sense to spend $5000 for a patent to protect a $1000 idea.
The products are relatively cheap. The SparkFun brand is well known, and by all accounts the marketing, promotion, sales & support is very good. This adds a barrier to any competitor.
Add these three points together and patents don’t offer any advantage for this product type & market.
Thinking that this applies to any company which holds a patent is wrong. If I have put $1M of R&D into a $1000 retail product, which does have innovative methods and techniques, then this is a totally different scenario than SparkFun. A $5000 patent is good protection for the product, and gives me some hope of recouping the R&D cost. As open source a $250 clone would quickly wipe out any hope of a return, and I would not have embarked on the R&D to begin with without that protection.
Finally, remember that patents are actually used to all the sharing of ideas via licensing without the fear of losing trade secrets. In that way they benefit many, not just the inventor.