First off are you sure its 50% or is that an exaggeration? i do about 100 customers a week and i cant imagine a scenario where 50 of them would skip lol, that seems insane to me....
The other week i had one day when i had about 5 skippers. Wondering what was going on that day! But thats a one off...
I always get the odd one skipping for various reasons, its only a problem when its the same customer doing the skipping but usually for me its a different customers for various reasons, holiday, work being done and occasionally the odd one who just skips for no apparent reason. As long as there isnt a trend with a particular customer i dont really care, i always add a couple of jobs extra to each days worksheet to cover it.
The only solution for you can be more customers, i have about 100 customers more than i can get round, which means of course im always behind but it also means i never have a drop in income or ever have to worry about someone skipping a clean...