Dryasabone has a good business sense but dry carpet cleaning sells well but isn't as profitable as wet cleaning (irrelivant of the which is best arguement) as the compaound is far more expensive.
The product itself is far better than what it used to be (powder) but so are the detergents and nondetergent formulas, neither system leave residues and I'm sure that both leave a good clean carpet (obvilously down to the operator) but the fact is that dry granular cleaning is far more expensive to do.
The cheap bit of carpet cleaning got expensive, the expensive bit (insurance, adverts, petrol etc) still is the same for both and NO dry cleaning doesn't get you more customers only YOU get you more customers.
Shaun