It means so much to be thanked - text, phone, or snail mail works! My grands all live in the US so they make a point of thanking me during the holiday call(s). The daughter's oldest is teaching his younger sisters to say thank-you - last week I heard him urging each girl to be sure to say something to Gran about their gifts. My oldest grandson (son's lad) made sure to say something Christmas Day but I was surprised and very pleased to also receive an email with photos of him using what he'd bought with the Amazon voucher I sent.
Their parents? Erm, well, despite a bit of a rough patch on-going between my son and his ex-but-possibly-back-to-current-wife, both emailed immediately on receipt, and also said thank-you over the Skype Christmas call, as did my SIL.
My daughter? No. I did chase her down as the Amazon voucher was redeemed within minutes (really, less than five!) of it hitting her inbox and I was afraid it had been hijacked. It took 2 days for her to answer my frantic 'Did you get the voucher?!' email. I'd be more hurt but she's always been this way - from around aged five she's been asking why I'm the mum and she's the daughter