Unique selling proposition is thought to be the killer ammunition for the sales team. What is unique today in your product will not be unique, 3 to 6 months from now. The same way you watch your competition, your competition is also watching you. Feature or a business model will go thru continuous change over time.
Chasing features
Product companies keep chasing features one after the other. This is a never ending game. If you feel that a feature is going to win the sale, it may be true today but not in future. Uniqueness comes from a combination of factors such as features, support, price, business model etc. So unless you have a unique combination of these to win the hearts, you may have to rethink in the near future.
You may replicate another product and still differentiate. For example the SaaS accounting products may exactly do the same as the other ones, but the differentiation is pay as you use model. Thus feature differentiation alone is not sufficient today.
Story is important
The story around your product and the pains that it solves are the ones that are remembered by customers. Customers will tell others and relate to these stories and not the features.
Creating a perception on the product is more important than the feature set.
Being low cost had been one of the USPs for many products and service companies. But this fades away with time and if the companies have not found another sweet spot, they will not be able to sustain the head wind.
Geographic Advantage
The USP of some industries may be due to the geography that they are located e.g. a resort in the Alps! These USPs are tough to get challenged and the early birds enjoy this USP. But the newgen looks for different kind of experience from food to travel to mobile apps. As the mindset of people keep changing, geo based USP is also changing rapidly.
Having a huge cash pile in terms of funding is looked as a USP for many growing startups. This is actually not true. Very successful startups like Atlassian have built up an empire from zero without funding.
Constantly communicating about the variations you bring in to the product itself is one of the USPs. The more you keep your customers informed, the more they will be the bonding level.