This is not a coding question, but I wasn't sure where else to look for an answer.
Lets say I have a product selection menu, some of the products are unusual, so I thought it would be great to direct my users to a new blank tab/window that directs to a relevant page on wikipedia. Is that legal? My thought for why it wouldn't be is that I'm leveraging the usability of my product off another organizations efforts. Sure I'm directing traffic to them as well... should I ask them first?
Read the Wikipedia terms of service (or TOS/AUP for whichever web site you are linking to, and consider emailing and asking permission). n this case the license does allow copying, to whit (for Wikipedia):
"All text is available under the terms of the GNU Free Documentation License. (See Copyrights for details.)"
Someone can probably close this question now.
At the bottom of all Wikipedia pages it says, "All text is available under the terms of the GNU Free Documentation License." I would suggest looking at the GNU Free Documentation License and be sure you're following it.
I think there is nothing illegal in this. I also think it would be fair to at least ask them, and to contribute by donations as well.
Finally, I would not put my trust on something I have no control if I wanted to deliver the best service to my customers. I can imagine such redirections on a company blog but not on a product description sheet.