But using poor grammar in a cover letter, spelling the client's name wrong, providing brochures that are yellowed, worn, or written on, or sending out something that just looks like poor quality clearly communicates the kind of work the client can expect. This applies to telephone communications, as well. A convoluted voicemail system or an unprofessional receptionist gives a very poor first impression. He'll have to call you back tomorrow. The amount of information available.
Some vendors seem to have a thoughtful answer to almost any question.
Others apparently can't believe they're being asked questions. Clients will often want details. These are all questions that should be relatively easy for a research company to answer. Yet all of them have, at one time or another, completely stymied the representative of a vendor with whom I've spoken. If the firm can't or won't easily answer questions such as these, a client is likely to go to another vendor that knows its business more completely.