There is a definite, strong link between sales and user experience. This happens because people are more likely to be trusting and willing to part with their money if their lives have been made as easy as possible for them. If you are going to prioritise anything whilst trying to guide people further through the sales funnel, then it should be user experience.
This can refer to any platform at all, be it a website, social media or another kind of advertising campaign. People should find the medium easy to use and understand, meaning they can access all the information they need, all in one place.
You should make sure there are clear calls to action, telling people what to do. This is especially important on a website, or on a social media campaign where you are trying to convert people. Tell them explicitly what they should be doing and what action they need to take, like getting in touch or buying now.