It's barely February. You're probably not thinking much about Valentine's Day. But in a large loft office in Manhattan, a few dozen 20-somethings have been aflutter over hearts for weeks.

'I have had a lot of practice,' said designer Christina Song, who cut a perfect heart shape, freehand, out of delicate, gold handmade paper. She scanned it into the computersystem at Paperless Post, the online invitation company.

Paperless Post is known for personalized digital invitations, usually sent by email, that create a paper-like experience. Now the company is expanding its offerings of cards pegged to Valentine's Day, the second-most important greeting-card occasion of the year, after Christmas. An estimated 150 million paper Valentine's Day cards were bought last year, according to the Greeting Card Association.

Delivered by email or through social network sites like Facebook and Twitter, Paperless Post's electronic invitations appear on the screen as an image of a paper envelope. Typeface can look as if it is letter-pressed or engraved. The card