How much to tip a guide on a "free" walking tour

€15 per person is a fair amount as a base. If they were really good, I toss an extra €5. I usually tip on non "free" tours too. I've been on few where I didn't think it was well-deserved.

I determine the tip based on the quality of the tour. If they do a good job they get a bigger tip. Sometimes you get what you pay for!

I agree with Michael. There is no such thing as a free tour. I would pay the equivalent of what that tour might have cost had there been a charge. For a good walking tour a 15 to 20 Euro is not unreasonable. We probably have done a half dozen free tours and each was super because they are working hard for their tips. And I have seen tourist who away without giving anything.

Depending on which company is doing those "free tours", your guide may have to pay for each of the participants who start their tour. That is why they take your photo at the beginning. Big discussion about the "free tours" last year on Ricks blog, if you are interested in knowing more about the biggest free tour company.
http://www.ricksteves.com/blog/index.cfm?fuseaction=entry&entryID=411 I went on the free tour in Edinburgh, and it was truly awful, a complete waste of time. I would much rather pay the going rate for one of the other tours. So, my question is why not go on the regular tour and pay 15 euro, rather than go on the "free tour" and tip 15 euro?

I agree with Andrea. If these folks really are enthusiastic volunteers who just love to show off their town they deserve a decent tip. If the tour is nothing more than an extended sales pitch in which the tour guide brings you to various overpriced stores that are paying the guide a kickback. Well, then the tour guide has already been paid and doesn't deserve a tip.

Wow. Thank you all very much for your input. I didn't know about the previous thread. It certainly was an interesting readI had never even thought of that happening! Because (at least from everything I can tell), the specific tour we have highest on our list is advertised (website) and conducted by only one man, I feel pretty confident I haven't walked into this trap. All of the reviews (from trip advisor, spread out over a pretty long time) all talk only about this single guy and how amazing he is-combined with a friend's personal story. ..I guess we kind of fell for him. :-) To answer Jo's question. I don't know why frankly. I've heard such great things about the tour and like the idea that it is just one guy, so the money goes directly to him. I just realized in all of this that I've never actually given specifics. We're waffling about one of the tours, but the one we're set on is in Sarajevo. Here is the website: http://www.sarajevowalkingtours.com/ Here is trip advisor:
http://www.tripadvisor.com/ShowUserReviews-g294450-d1908837-r103039767-Free_Sarajevo_Walking_Tours-Sarajevo.html#REVIEWS Again, thank you for all of the advice. If we are looking at other tours, I'll definitely consider itparticularly the link that was posted.

Free Walks usually have no fixed price, tip based only. In Hungary all "Free Budapest Walking Tours" guides are insiders and they work only for tips. Tipping is NOT compulsory for any of the free walks (General, Communist and Jewish Quarter) and participants are free to give as much or as little as they feel the tour is worth, and is therefore available for everybody and anybody interested in Hungary. This system is also motivating all the tour guides to provide their best performance.
Agnes- Free Budapest Walking Tours

So, Jamie, this means Sarajevo is back into your itinerary? Yay!

We took one of the aforementioned free Budapest walks, and I think most everyone in our group tipped 1000Ft (or about $5) each. If there are enough people in your group, follow the herd if their tips don't seem exorbitant.

The above being said... anyone been on the 5 pound Westminster London walk or the Amsterdam free city walk?
Any thoughts?