I still don't get how you come up with 0,25% to 0,5% with BF. There's a 0,5%-1% fee on sales, so a flip will include that no matter if the buy is 0%. They say in the FAQ that if you are a day trader, you can get the fees down as low as 0.25%, but for most small to medium investors, that's not going to be an option.
Do a ฿100 buy and sell, regardless of time span, and you'll be out between ฿0.5 and ฿1 on Bitfunder, but always ฿0.4 on BTCT. I can't see how that's even; BF is at best 25% more expensive and at worst 150% more expensive.
0% fee on buy and 0.5% to 1% fee on sell = average fee on a transaction (buy or sell) is (0.5% - 1%) / 2 = 0.25% to 0.5%
My point was that with the dividend fee and withdrawal fee, it might be a wash to better if you qualify for the discount. The tiering is based on the last 60 days so one doesn't necessarily need to be a day trader, just buy/sell a combined 50+ BTC in 60 days to start earning discounts.
And also you can avoid the sell fee by accumulating more than 250 shares and transferring out to non-passthrough shares as mentioned by someone else. A strategy is to buy cheap PT shares and accumulate/dividend invest, and supplement with non-PT shares purchased through auctions and transfer those to PT shares.
If the dividend fee is going away then for a buy and flipper btct.co is better. But for a longer-term buy and holder, BitFunder can be better because you can avoid fees altogether (sale or withdrawal fees).
Plus I will believe that the dividend fee is going away on btct when I actually see it written down in the details or there is a motion passed.