I'm wondering if anyone has seen a memo with the text "offer_via_sp" - which, in my experience, also includes a withdrawal/sending of an amount of lumens with it. I did not send them myself, but almost seem, like a fee along with a transaction, though I don't believe that's what they are.

Has anyone seen or had transactions with "offer_via_sp" in the memo section?

You created an offer with Stellarport hence the memo offer_via_sp.

Market makers (who add liquidity to the exchange) do not pay fees at Stellarport, while market takers are charged with 0.15% per trade.

Ah, ok, yes - of course. I made a few different transactions and didn't put the 'sp' and 'stellarport' together at the time. Thanks.

How do you know if an order adds or removes liquidity though?
An order might be completely fulfilled, partially fulfilled, or not fulfilled at all, just based on timings/other orders.

    dzham

    I guess in this case:

    market makers == limit offers and
    market takers == market offers.