If we're talking big ideas, in my opinion branding, positioning, strategy, concept, etc. are all tools to achieve three key ideas - ideas that result in sales:
RELEVANCE: does this product/service/company mean anything to me?
AFFINITY: do I feel any closeness or interest in it?
TRUST: am I willing to risk my money/reputation on a purchase from this organization?
The tools are necessary too, but don't necessarily lead to conversion.
I would also say (or as Malcolm Gladwell would say in "The Tipping Point") the "sickyness factor". Will they remember this and think about this ad during their entire day?
1) Brand building & sustenance- one brand, multiple messages and adding strength from one message to the next
2) Interactivity- based on consumer insights & engaging target audience
3) Emotional perusasion- inspires, indulges, humors, teases
I think whatever tool / medium is followed or say whatever strategy is taken; unless and until the advertisement doesn't communicates the message (profits / benefits of the product being advertised) to the prospect, the purpose is not solved. So, advertisement should COMMUNICATE the message in well crafted words.
Next, the advertisement should CONNECT to the prospect. It should either solve one (or more) of the needs or create a need in his eyes and mind. In this way the idea will be to create an urge to buy the product being advertised.
Advertising on these lines will definitely transform any prospect into "CUSTOMER".