starting seeds in cardboard rolls has the same main drawback that using cellpack or other cardboard/plastic containers have, the roots can easily become pot-bound. i just
compost paper rolls with the rest of my paper trash.
i started using soil-block makers this spring and have been VERY happy with that purchase!
they work amazingly well,plants are very easy to transplant this way. search on google and youtube for them.
we must've made over a thousand soil blocks this year for starting seeds, and they all did really well.