Hello,
I have a reasonable 0% BTC buy offer (just about 0.18 BTC) running.
What is the recommended time-frame until I have to assume that there is no interest in my offer ?
All fees are lost when I cancel my buy offer ?
It depends strongly on which market this offer is.
Look at the realized trades, and you’ll get an idea.
For what I remember you don’t lose much.
If you are regarding for your fees … use BSQ. It’s 90% discount.
Well, 4-10 trades per year 
Possible wishful thinking on my site…
Statistically you will have to wait 1 or 2 months then. 
Try advertising your offer on other media platforms related to your market.
Most people can’t buy BTC with FIAT anymore since 1.1.0 was released, the limit is now 0.01BTC which is too low to even be bothered
Wait a month or two for the new release then try again.
You can always make multiple offers if the limit is too low for you.
also I can only strongly suggest for people who want to sell and are looking for trading partners.
always give a range of BTC that you are willing to sell not only a fixxed ammount of BTC
I was so often in the search for BTC but just saw offers that were 500€+ without any room for suggestions, and I needed maybe like 400€ right there and would’ve been glad to buy 400
it’s more likely you’ll get a faster trade going when you give the buyer the option to choose the BTC amount according to his needs.