I noticed something odd when searching for accommodations on Airbnb.  My initial search turned up some results I was interested in, but when I logged in and re-did the search, those results were no longer there.  I know the places existed and were available, because I ended up booking one of them (by copy-pasting the URL from the initial results).

Has anyone else experienced this kind of thing?  I am hard-pressed to see this as anything other than a deliberate strategic exclusion by Airbnb's search algorithm.  I have heard of online retailers using variable pricing depending on the buyer's demographics.  So are they just trying to wring more money out of my by hiding cheaper places?  What other explanations are there for this?