due to its instability and short term life. my own position is that you can't escape material parameters, so you should sell work of more permanence. it is really most of an issue for museums. I think the computer program is important for long term translation, but again that would make the result different through the use of different hard & softwares.
performance art is not about selling, but raising the profile of the artist/artists, therefore
>This way the collectable object functions more or less as a share in the project/work, or in the artistic activities of the artist.
is a good way of looking at it
I think the real issue lies with curation in terms of how less sellable work is preserved, as it obviously benefits the longer it can be kept (working or not). People in general only tend to truly appreciate the work when it's about 50 yrs old! Then it can be seen to have anticipated change that has meanwhile taken place.