I ordered a mattress thru Wayfair about a year ago, for my daughter. I thought it'd be thicker than it ended up being once it puffed itself up. So her deep pocket fitted sheet didn't fit it well, so i decided to add some thickness with this mattress topper..which did help. So I'm happy her mattress cover, between the mattress & the fitted sheet, isn't as loosey-goosey as it had been.