Have heard similar things about Rishworth's however there is something to be borne in mind.
If for instance the position is in a poorer country then that is reflected in the salary. An agency, on it's database, may have several hundred suitably qualified pilots, they haven't got the time or resources to contact all individually thus they will 'mailshot' all as one.
That mailshot is sent to everyone suitably qualified, accepted that a pilot in Western Europe may turn his nose up, take offence to the salary on offer but at the same time a pilot in, effectively bankrupt, Argentina will already be packing his bags to take up the position at such a good salary.
Both pilots are equally and suitably qualified, one doesn't want it, the other one does!