What makes advertisements attract attention?

On Monday my professor had brought in advertisements from several magazines and wanted us to answer questions pertaining to our ad.  I wanted to pick one a part a little bit.

Who is this ad trying to reach?

It didn't reach me.  The cap of the bottle is pretty but that's about it.  Who is the girl holding the bottle?  Is she significant, or a model?  Does she work or model Marc Jacobs & if you love/know the brand then you know who she is?
The ad is trying to reach teenagers in my opinion and why I say that is because of the girl who looks like she is 16 or 17 years of age holding a very colorful bottle.  If the girl was 25 or 40 and the bottle was black then I would say an older audience they are trying to reach.

Usually ad's for perfume are sexy, provocative or have star power with Beyonce, Charlize Theron, etc... In this case in particular it has none of those and sometimes with a teenage audience you don't need anything flashy.  Just a girl your age you can relate to with an attractive product.

Last year the candy brand known as Mike & Ike announced separation.  As a gimmick Mike's name was scribbled out.

Now in 2013 they relaunched the reunion of Mike & Ike with a mini movie commercial. 

Why did I bring this up?

Mike & Ike are known by my parents, grandparents and younger cousins.  The company has been around for 70+ years and for a company to stay in the game that long especially in today's time you need something to keep it fresh and new.  This was their advertisement to keep people laughing and thinking about it.  Not to mention the ad they made for the reunion was a mini movie that is really entertaining and appeals to buyers both young and old.  In this scenario you needed something flashy because you can't just have an ad or article that says their back together and that's it.  That would have been boring and you'd be wondering why they split and how they got back together.  Also this opens the door for these two actors who are now the "faces" of Mike & Ike for future ad's.  It could be a mini movie montage for a while which would appeal to those who loved the first mini movie commercial. 

Companies have to, I believe put a lot of thought in to their advertisements and marketing because you have to know what will attract your buyers and specifically what buyers you want to attract.