The "hold immediately" on the packaging does not mean that the hook (or whatever) can immediately burden fully. It's just that the hook does not he must continue to press the adhesive surface does not drop again thus. Wait until the adhesive has cured you should then already. After all, on the packaging that the final strength is reached after 48 hours.
For me the whole thing holds half a year. Nix nix loose and fallen off.
Some reviews I read out that an attempt was made to stick plastic. On the back of the package is indeed on it that this glue is not suitable for PE (polyethylene), PP (polypropylene), PTFE (polytetrafluoroethylene), natural stone and thin source sensitive wood ... Maybe lags so that nothing has kept .. Or because of which the area has not been cleaned properly.
It would be helpful if yes here on Amazon from the back of the package also a product image would be set. Then some people would not buy the wrong product and then tease .. I would probably have gone the same way if I before buying the back would not be able to read. If the product description is here that is also not accurate for use and processing ..