Shipt does the same thing for some stores they deliver from. They claim something like a 15% markup average, but in reality from our own experimentation on items we most frequently purchased, it often hit 35-100% markups and higher. (Actual examples: a $5 watermelon for $12; a dozen store brand eggs $0.99 in the store but $2.99 from Shipt). Add tips and it's rarely worth it for us anymore.