I'm turned off when someone describes their startup as "the $successfulCompany of $otherIndustry" or "$successfulCompany for $otherIndustry" for three reasons:

1. It implies that copying a successful model is easy. Companies are rarely success stories based solely on a great idea. Execution usually matters more. It's worth asking a founder if they know of examples where the $otherCompanyName model has been applied to other industries and whether it has worked or not. Ideally they should be aware of successes and failures, and be able to identify the root causes of each.
2. It's an oversimplification that lends itself to a variety of interpretations. One company I looked at recently pitched itself as "Facebook for Things." What does this mean? Do things have friends? Photo albums? Do they poke each other? If you're going to try positioning your company in a single sentence, it's important that your audience is left with an accurate idea of what the company is. Even worse than ambiguity is false certainty. If your positioning sentence makes someone believe they understand what you are, but you're actually something else you run the risk of being ignored by people who might be interested in what you actually are, and turn off people who are excited by their false interpretation but find that it's not who you are.
3. Original ideas are more compelling than adaptations. I'm far more interested in a company driven by a specific passion around an original idea than one that feels like it was created around a matrix of successful companies on one axis and niche industries on the other.

Homework: Look at successful companies and see what "$successfulCompany for $otherIndustry" might have fit them when they were just starting up. Tweet your answers with the hashtag #UberForPizza and we'll compare notes. Update: Okay, okay. "Uber for Pizza" is a great idea, it's true. But it's still ambiguous. Is it a single number or app that will send your request to the closest/most available pizzeria with delivery? But Uber is all about higher quality than regular cabs, so maybe the company operates (or subcontracts) a fleet of vans with half-baked pizzas and flash ovens which can bake and deliver a pizza of consistently high quality in 8 minutes or less. Or maybe it's a taxi service where fresh pizza (and breadsticks) are baked and served inside the car as you make your way to your destination. Mmm, delicious ambiguity...