PayPal Holdings (PYPL 0.34%) cruises into 2016 determined to increase its market share in transaction processing, as well as to become a primary in-store option for retailers seeking to increase interaction with their customers via mobile technology.

Of course, there are bound to be kinks in the path to transaction dominance, as the company moves further away from its business model under former parent eBay Inc. (EBAY 0.88%). Earlier this month, we took a look at PayPal's best business category in 2015. Let's follow that assessment, which you can peruse here, with a brief look at the company's worst category this year. To view this category and to understand why it presents a drag on PayPal's business, simply click through the accompanying slideshow below: