Considering yours is a paid service, I would hope you're already thinking of something else, because im sure the FB TOS will block you and besides, if someone wants a customizable free version then they just use tumblr with one of the millions of these (or make one by hand)
If your product service offered a channel from instagram to tumblr and it didn't violate the TOS for FB then your product might have a future, but likely only as a free offering.