Here's what I do.
If it is a neice or nephew (all mine are under 7)we send a card and dollars for their age- like 3 dollars when they turn 3. We also try to call them and sing Happy Birthday. If we are in town (we live 30 hours away) and they have a party, we go to the party and bring a gift. If it is a godchild, we send a gift every birthday.
If it is a my brother, sister, SIL, or BIL,(we have 10) I send a card but not usually a gift. Randomly, I may send a giftcard or a gift, but it is really about me finding something appropriate or because I know the person loves getting gifts.
I also send cards to my MIL, FI and my own parents and grandparents.
Who sends to us?
My sister (whom I'm very close to) rarely sends anyone anything. She will just call and wish happy Birthday if she remembers. She doesn't believe in cards/gifts.
My brother(s) both send cards and often money to my kids and just cards to us.
My inlaws all call/email/fb and my MIL and FIL send money, usually a hundred bucks (which I find ridiculous) to me and my hubby and both my kids
With my closest friends, we often send a card, but no gift. But it seems to be switching to Facebook. I think that would be great since it is expensive to buy and send so many cards. At the same time, it is fun to get em on your birthday.
With local mom friends, we exchange babysitting on birthdays and anniversaries. It's a great gift! The gift of free "free time".
I would say that you should do what you feel comfortable doing. If you like to give cards like I do, then do it. No one is going to be offended if you do. Just don't expect anyone to give them to you because not everyone is into it. If you wnat to wish em a good day without a card, use FB or email. I love those messages to because at least you're remembered.