A guruwalk is a tour, usually on foot (there are also bike tours, etc.), lasting between 2-3 hours. The theme can be varied (essential tour, thematic, districts, mysteries...) and the guide is an expert on the subject.
So far, you will see that there is little difference between a conventional tour and a free tour. The peculiarity of free tours is that the traveller pays at the end of the tour. Depending on the experience they had, the payment may be more or less generous.
This fact allows more travellers to join the tour freely as there is no "pay-as-you-book" brake. This is one of the reasons why the free tour has become such a popular experience. Added to the fact that free tours offers these multiple perspectives of a city in a very affordable and entertaining format.
We always insist that it is very important to have a great deal of knowledge about what you are telling the traveller, but that it is more worthwhile to offer a memorable experience than an overload of facts, as this is what the traveller is looking for when booking a free tour.