overhype 
verb [with object]
Make exaggerated claims about (a product, idea, or event); publicize or promote excessively: the film was overhyped by the press...
- The idea was heavily overhyped by the anti-PC crowd but it's not clear that real sales ever got out of double figures.
- When so many overhyped events fail to deliver, this should be a welcome refresher course on how to have a good time.
- We all know that New Year's 2000 was one of the most overhyped events of our lifetimes.
noun [mass noun]
Excessive publicity or promotion: the hard sell and the overhype make the discerning fan suspicious...
- Worried about speculation and new-club overhype, the owners kept the very existence of the bar a secret until only two weeks before opening last August.
- To avoid the unnecessary overhype, I probably would change the headline to ‘may change your world’.
- Their biggest fear now are the sharks of overhype.