Complex sentence: This effect can e.g. be employed for computing the QR decomposition of a matrix; one advantage over Householder transformations is that they can easily be parallelised, and another is that for many very sparse matrices they have lower operation count.
Split into simpler sentences: This effect can, for example, be employed for computing the QR decomposition of a matrix. One advantage over Householder transformations is that they can easily be parallelised, and another is that often for very sparse matrices they have a lower operation count.