QR codes are drives traffic to your website especially now that most of online surfers use smartphones or tablets to view websites rather than their computers and laptops. The major advantage of QR codes for your blog is that you avoid the competitive search engines. By using QR codes, you provide links so customers directly access your site. So much for racing on top of search engine results, QR codes delivers traffic like no other.
QR codes are easy to create. In fact, there are a lot of QR codes generator online you can use. However, if you want your blog to have QR codes to every post, using such tool is not recommended as it consumes time.
WPRecipes suggest this code to help generate QR codes automatically.