Seems Like a Great Idea for Parents.
This idea strikes me as nothing short of brilliant. Grandparents, aunts, uncles, friends, teachers, etc. could all easily contribute items and a terrific, date-stamped archive would be there waiting when the child grows up. I wish I'd thought of it when my kids were little.
Is there something I'm missing? Other than an email provider going out of business or limiting storage, I can't think of a downside.