I remember that, a few years ago, two French smog check companies had ad campaigns explicitely comparing each other, even though they were actually owned by the same group and were providing the same service, just under two different brands.
The goal was to raise awareness of both brands at the same time and make each other look like a leader in the market: if company A is comparing itself to company B, it must be because company B is a leader. (didn't Fedex do something like that by presenting itself as #2?)
I can find plenty of reasons why it would be a terrible idea: brand dilution, distraction from actually building the product, extra work…
But I can also think of reasons why it might work: you're effectively A/B testing your whole branding; if you create a market, having two "players" makes it look more important; in some cases, people want to be able to compare, even if the products end up being the same thing, etc.
What do you think? Have you done it? Do you have examples of successes or failures with that?
I did some work recently for a company doing SaaS for small businesses. Their product was quite easy to use but difficult to sell, with a huge number of pre-sales enquiries about whether the product would suit a particular business. A lot of work went into improving the website to answer that kind of question, but nobody really bothered reading any of it.
Eventually, they bought a couple of hundred domain names and wrote unique copy for each, emphasising benefits and savings specific to a particular business. The product itself was identical across all the branded sites. Sales skyrocketed, covering the cost of that work within a matter of hours. Every part of the funnel improved substantially - more search traffic, better ad click-through, cheaper clicks, lower bounce rate, better conversion. Curiously, there was also a marked improvement in retention.