Why does Coinjar only have up to 4 decimal places for bitcoins, compared to 8 decimal places for Swyft?

Could they potentially be skimming the remainder as profit? If you keep adding them up with each transaction, and with BTC continuing to rise in price, that could actually be a substantial amount for the company.

Edit: I should probably mention that I've been using CoinJar for a while and mostly find them reliable and stable. I've never had to interact with their customer support, but you could almost interpret that as being a positive in that I've never had an issue to complain about. Can't really comment on their fees as it's not something I've really compared with other exchanges.