As well as not stuffing them full of chemicals, for me is saves money as Cairo is a big horse and needs a lot of wormer.
Just pop a poo piece into the sample container and post it and they email you back the results very quickly.
They also have a suggested worming programme on their site. I do one less count as I have done this for a few years now and you can reduce if you keep having low/clear counts.
Whole yard (and one next door) has converted to this method of worming.
I use worm counts too, although I use http://www.abbeydiagnostics.co.uk/
Having had nothing but <50epg for years I have only wormed for Tapeworm every autumn ,Dr Chris Dolby is fantastic if you need any advice.