Unless you spent the last couple years living under a rock (and missed Serious Eats' post from 2008), you've already heard of Baconnaise, "The Ultimate Bacon Flavored Spread" ($5.99/15-ounce jar). For the handful of you who aren't familiar with the product, Baconnaise is mayonnaise that tastes like bacon even though it's vegetarian and kosher. It was created by J&D's Food's, which started with several varieties of Bacon Salt before expanded to include Bacon Pop (bacon-flavored popcorn), Mmmvelopes (bacon-flavored envelopes) and Baconnaise.
I was pleasantly surprised to discover that the smoky and salty flavor of Baconnaise works well on a juicy burger. The smokiness, achieved by adding "natural smoke flavor," paprika, onion and garlic to a mayo base, is the most prominent feature of Baconnaise. The flavor reminded me of tangy mass-produced barbecue potato chips, which also use "natural smoke flavors" and liquid smoke, made by rapidly chilling the moist smoke off of smoldering wood and collecting the condensate.
Baconnaise works fairly well as a sandwich condiment, but the assertive smokiness can overpower mild ingredients. Try it smeared on sandwiches you'd normally make with bacon if you're low on time (or bacon). The key to using it for tuna salad is to use half Baconnaise and half regular mayo. If you're up for an adventure, whip up a batch of Baconnaise Deviled Eggs.
Due to Baconnaise's powerful flavor, I'd shy away from using it as for a dip, salad dressing, or in a fish dish.
While regular Baconnaise has the familiar, thick consistency of mayo, Baconnaise Lite is runny, which makes it harder to use as a condiment. Unless you're a bacon addict on a calorie restricted diet, I'd strongly advise sticking to the regular.
And if calories and dietary restriction are no object, follow Kenji's recipe for making homemade baconnaise with strips of crisp bacon and rendered bacon fat.