Regarding the card selling business and having looked at their site, this is my view on selling greetings cards.
I make and sell my own cards, they are all unique and original made from silk, felt, beads and other little bits. I have sold them through shops and through my own website - www.raspberry.co.uk. The info is out of date but the cards are not.
Well selling through a shop was ok, but I lost half the value of my card in their cut, but thats the way it is, on the website it has gone ok, and I recieved a commission to make 30 wedding invitations which was great.
But, and there had to be one! You need to have something different to offer, not what you find in the shops and looking at the Phoenix site the cards are very similar to ones you would find anywhere else and not that much cheaper, especially from the cheaper end of the market such as shops like Birthdays and Clinton Cards.
If you know lots of people that send lots of cards, (my MIL is the biggest purchaser of my cards!) then you are fine but otherwise you could have problems.
I found the bestsellers were and are still, wedding cards, christenings and valentines, because people are prepared to spend more on a special card.
Hope this helps and I haven't waffled too much!! If you want to ask me anything else, please contact me through my site.
Godd luck with the cards if that is what you choose to do.