Can you sell -YourDomains, on a flippa auction, AND on a sedo auction at the same time? eg can you sell them both on the 1st of June, on both sites, together ? Have you done this for your domains?? did you find one site gets more bids than the other? and one offered higher sales ?
You'd need to read the TOS of both sites. I would imagine that if you secured a sale on one site it would be legally binding and to risk selling on both sites simultaneously would be "problematic". You can't sell something twice.
There should be no problem if you decide to sell a domain on two or even more platform, The platform cannot detect and also won't forbid you selling the domain elsewhere as it's your whole right. But if someone buys your domains at Sedo, and then buy it on Flippa, you're under risk -- you have only ONE domain, and you might need to pay penalty or get account banned. Always suggested only sell one domain in one place. Exception is, sell the domain with fixed price on one platform, and sell it on other platform with accepting offer model, there's no risk on accepting offer.
I think you can do that, you list your domain with specific price (BIN price) on one site and on another site you list it with negotiate price. This will help you to decide which price you can sell or you can cancel negotiation at one side. IMO
I personally perfer to try to pause it from sale while it is listed elsewhere. Once it is for sale at an auction, such as flippa, the sale is "locked". For most auctions, you are legally binded to continue the transaction. skim read this: http://www.theaustralian.com.au/remote/check_cookie.html?url=http://www.theaustralian.com.au/news/nation/aircraft-in-ebay-dogfight/news-story/50d31ce2ea5ef1093bfe32b2eca4cbce It is always good to take auctions seriously. I do realise that it can be frustrating. (above url looks wierd, the DP forum claimed the correct link was redirecting to the above, so i had to put that in instead. go figure.)
It depends what kind of sale you are going to make. If you are going with the "make offer" option then it is not a problem as you will agree only to one of the offers. But if you choose an option that you have to sell it at the end then it could be a problem. Check all the options and terms before doing that.
It depends if you're listing in the Flippa portfolio or as an auction. If you're listing as an auction then you shouldn't. If it's just in the portfolio section then you can list with as many places as you'd like..