Greetings Cards developing a concept

I am needing to start the two YCN briefs now so that I can ensure I leave myself enough time to get the most out of them, these include the UK Greetings card brief and the Lego brief.

I need to pick a theme for the cards brief, initially I was going to continue with the theme I used in OUGD301 for the same brief, but then realised I cant submit the same or similar work twice. What I was thinking was to come up with a concept that wouldnt be an easy option, like birthday cards. So the idea is to come up with little messages that can just be sent whenever, like cards saying hello or how are you. Just to make somebodies day. I dont think there is a huge market for this type of card and there is a lot of scope.

I am going to have to come up with a solid concept and design approach for the greetings cards, along with a brand and identity so that I can produce POS and stuff for it.

The first thing I am going to do is come up with some card content ideas to see how I could make my idea work in an interesting way.