We already know that there will be a large scale LEGO Marvel Avenger D2C set coming in April and thanks to instagram user igna_sj_2003, we have the first images to the accompanying gift with purchase.
It features a micro-scale Avengers tower with a micro quinjet along with an exclusive Iron Man minifigure. According to the instagram account, the set was accidentally put on the shelves in a LEGO Certified Store in Europe.
This looks to be a nice gift with purchase along the lines of the Harry Potter Diagon Alley (40289) promotional set which was redeem when you spend a minimum of USD$99 on any LEGO products. I would expect a similar promotion for the Avengers Tower (40334) as well.