What are the aspects of sales promotion?

Some aspects of sales promotion are:

It provides low-risk introductory deals so buyers drop their hesitation right when the offer reduces uncertainty about the purchase.
It pairs a checkout-zone price slash with sampled displays so buyers try the product after seeing how well it matched their preferences.
It distributes free mini-units during community events so buyers judge if the quality aligns with what the brand claims.
It gives extra points on repeat orders so shoppers confirm that their regular choice is still the most beneficial.
It bundles complementary items together in larger packs so buyers compare which combination suits their usage habits.