I am seeing more and more people skipping right on by any females where the seller is retaining the right to a flush or a embryo interest. More and more people do not want to have the hassle of having to deal with this in the future. I agree that some sellers are retaining these interests, in an attempt to make their female appear to be more valuable, but I think in many cases, it is backfiring on them. The only times it seems to work is one a few of the very top females in the breed.
I also see the same thing happening with bulls where the seller is retaining a semen interest or a share in the semen sales. I used to do this occasionally myself, but have completely stopped doing this for the past several years. I hear more and more bull buyers saying, that they are not interested if the seller is retaining any part. There are probably several reasons for this. I have just decided that if I want to use a bull I have sold, in my herd, I should be able to purchase some semen from the new owner or try to buy the bull back some time in the future. Buyers are becoming very selective and that is their right.