One neat thing I recently encountered is that people are listing apartments with fees as "no-fee" on StreetEasy.

That is, I inquired about a no-fee listing and was met with "actually, there is a 15% on this listing is that ok?".

To address a sibling comment, there are still bait-and-switch listings as well. Many of these are listed as having been on the market for 50+ days. You can spot these placeholder listings with practice. They're especially common with larger, managed [airquotes]luxury[/airquotes] apartments.