Well, yes, that's always been like that: single trips are disproportionally more expensive than return flights with the majority of the airlines. And the principle of an open jaw is that you book a return flight which consists of two 'single' trips, as the return airport is different than the departure airport or vice verse. Most airlines offer this as a standard feature. And usually top deals only apply to return tickets, be it a regular return, an open jaw or a double open jaw. Most airlines actually have fare rules for single trips when combined into a return so it can be easily calculated how much a flight would cost if part of a return ticket (be it open jaw or not) if flown under the correct conditions: my online TA for work displays these fares explicitly in its booking engine. In that case it's simply to put together two such fares for cooperating airlines or the same airline to get a price for an open jaw return.

As said in the previous post: your site isn't manually updated with fares people find and share there. Proof was the AB fare from Berlin to unknown. I do not exclude the possibility of screen scraping yet, although I find it quite plausible that some API is used to program some sort of application for fare finding. I (again) assume that Amadeus is the engine here, as certain airlines are clearly excluded. I do, however, question if it's done with brute force, as that would significantly slow down the engines. I assume that there's some algorithms behind it that scan for specific parameters of deals. It probably has to do with zones or distances, price level, comparisons with competition on the route, booking classes and probably even sudden dramatic changes in fares, if a history on fares is kept.

I honestly never heard about your website and I do know a load of online travel agents who offer low fares on -and that's nothing new either- only specific dates and flights: I can't recall any of these using your site as their source, as most deals there seem to be not exclusive (though some fares really seem like possible error fares). As stated, for example the WAW - SSH fare was also directly bookable with LX. I haven't seen your site on the MileageRun forum either. Anyway, any source for cheap tickets is welcome for me, I'd say, this is just another one.

My 'secrets' for finding cheap deals are quite simple:
- subscribe to all airline spam to see which routes are on sale
- keep an eye on the mileage run forum (and share if I find something myself)
- use sites as SkyScanner, Kayak and ITA to find out if cheap fares are even sold cheaper anywhere else
- keep an eye on sites that regularly (claim to) advertise error fares (like 'holiday pirates')

As most of my traveling is job related and thus paid for by others, I don't need too much of those deals, as I don't have time for private traveling that much anymore. That's also why this system works fine for me.