Never heard anything so ridiculous in my life.
Your original price could be £100 yet you end up with £20 after Vat....so basically you are letting 80% of your turnover go (presuming your,e not VAT registered) in order to get good exposure.
Surely you would be much better off taking 80% of your current turnover and employing canvassing teams to get new work at the true market value.
These schemes drive prices down to unsustainable levels and are not only damaging to you but also potentially the trade in general.
How many of the customers that actually pay £50 instead of £100 (example figs only) will willingly sign up long term,they are bargain hunters who have caught onto the fact that desperate companies will offer something for nothing just to get new business in.
I certainly do not hope that it works,i dont wish bad fortunes on your finances personally (you're doing a grand job of that yourself) but i can see every desperate wc/gutter cleaner/upvc cleaner looking at this with rose tinted glasses.