does it cost money for the datasheet?
Not right now, but it I wouldn't be surprised if this changes once they
think they have enough people locked-in.
These sites come and go. Beats me how they cover their costs. I doubt
pay-per-click advertising pays enough.
Some of them are offshoots of those "brokers" who list every device in
existence to get hits, then can't supply when you inquire. (The "throw
enough shit and some will stick" principle)