I`d say go for it, pretty much every contract I have pay another company to clean their keyboards and phones.
I have been thinking about starting it myself.
in a recent experiment at some university somewhere ( got it all written down somewhere but I`m sorry I can`t be ar$ed to find it)
anyway,
they tested a toilet rim and an office keyboard and found more germs on the keyboard than the toilet.
another good one is if you go in to an office with an A3 piece of white paper and put the keyboard up side down on it and tap the bottom a few times you usually
get allsorts of cr@p fall out.