Wendy's is hoping its rollout of a pretzel bun will boost profits. The Associated Press reported in January that the fast-food chain was testing the "Pretzel Bacon Cheeseburger" in select locations. Then an analyst for Janney Montgomery Scott recently noted that executives said the burger would be rolled out nationally this year as a promotional item. That has sparked plenty of online chatter, mostly positive. But the concoction wasn't created just to please taste buds. The burger is a reflection of Wendy's emphasis on offering more premium breads that raise perceptions about the quality of its food without raising its own costs too much.