Make it inviting

Conundrum:
In order to sell something, it has to be different. If is is different, it is unfamiliar, and unfamiliar stuff is hard to use. Ergo, in order to sell something, it has to be hard to use.

Problems with this:
Something does not have to be different in order to sell. People buy the same old stuff all the time. Selling the familiar or following general industry trends then comes down to marketing muscle. Who has the biggest marketing budget?

Unfamiliar stuff is not always hard to use. Familiarity is a scale, its not either or. Is is a little unfamiliar? That's ok. Is it very unfamiliar, in fact completely alien? That's not so good. Affordance and learnability is more important that ease-of-use. Make something inviting, provide natural feedback and people will learn it quickly. In fact, they will enjoy learning it. The advantage of learning something is that it gives people a sense of accomplishment. Very important motivator, and one of the strongest indicators of happiness.

Don't worry about making stuff different. Try to make it inviting.