For years telemarketing has been the primary way that sales organizations contact and secure new merchant customers. For the most part, these salespeople are paid on new account activations and are unreachable in the event of a problem or if what was promised does not turn out to be correct.
One of the most common approaches is to say that your credit card terminal is non compliant and soon you will not be able to accept credit cards. This is designed to get your attention and begin a conversation. Most find that this initial contact will lead to multiple calls and persistant atempts to make the sale. in nearly all cases, if you are using a peice of equipment that is nearing "end of life" status, your current processor will contact you in plenty of time.
Another is the "too good to be true" price qoutes. I get calls from clients regularly about companies who have made proposals that are clearly below cost. The problem is that once you are able to see the actual cost, you have already made the change and are left to try to solve the problem with the people who answer the toll free number. Good luck. Anyone can put any number on a spreadsheet but what you are actually charged is what counts. Always ask for references.
The worst are the companies who claim that they are calling from your current processor and need to send you a new terminal. They will claim to need to verify some of your account information (in order to set up the new account) then send an inexpensive credit card terminal. Once the terminal is used you are left with two merchant accounts.
These are just a few of the traps that I've seen over the last 10 years. I always provide references and comparisons to prove that the pricing I've promised is what my clients will actually see .