How popular is Wire Transfer.....

Wire tranfser is a fools way to lose the money.
A bank transfer is at least tracable. A wire transfer is sending money to any scam artist who can sucker the bait into sending it.
Of course some honest person may want it.. but no way is it a safe way to send money. So sending cash via Western Union, or some other cash to go place is foolish.
On the other hand a bank transfer is from one bank account to another. The recipient has to have a legitimate account, and in the case of fraud, you have a real target to show the police where it went.
(But be aware, they send the money to a NUMBER, that is it. If the number is in error, you are gonna have a hard time getting it straightened out. Use a bank transfer for big ticket items, or international only.IMO)
With a wire transfer, they will just tell you "too Bad" nothing they can do.
Sending money orders is another way to send money. Bank money orders are expensive, and can be forged, same for certified check. The best money order is a United States Postal Monney Order. It is cheap to buy, easy to send, very reliable,and is you trust the buyer, can bo deposited in your checking account just like any check. If you feel concerned about the buyer, you can go directly to a US post office and cash it for cash, right on the spot. (IF the post office does NOT have enough cash, and most will not!, then get as much cash as they will give you, plus buy a NEW postal money order for the rest of the money. Then you have a guaranteed real money order you can deposit in your checking account as you bought it yourself, for this 'peace of mind' the cost is about $2. for the new PO money order)

There might be a terminology problem here. A bank transfer is often referred to as a wire transfer so wire transfers are common and are safe when they are bank to bank.

Western Union transfers are frequently used by scammers because you can collect the funds by simply giving the code number to the Western Union office and picking up the money.

Avoid it at all cost. I can't agree with Elizabeth enough. And I like to ad if a seller is asking for either wire or bank transfer. Even if honest as the day long they should relize that it can and will raise a red flag. Use only a paypal type system or credit card. I will only send personal or money order when feedback is high. So don't feel bad thinking you missed out on some good deals. You might have saved yourself allot of headaches and money out of pocket.

I have not used Western Union or other wire transfer methods which don't use
a bank as intermediary. I, however, use the term 'wire transfer' to also refer to
a transfer between my bank account and yours.

It requires going to your bank and asking to 'send money' to an account.
When sending money internationally, there is a set of information required. It
is usually: Recipient's Name (also known as Beneficiary's Name), his/her Bank,
Bank Branch, Bank Account Number, and Country. It is helpful to have the
Physical Address of the Bank Branch and of the Beneficiary, but it is not
always necessary. You will likely need the SWIFT code (the international
version of the 'ABA Number' or the 'routing number' as used in the U.S.) of
the foreign bank as well. Many banks will require that to make an
international transfer. Anyone who is in the habit of receiving wire transfers
should be able to provide you with all of this information readily. All of that
information will go into a formatted electronic message to be sent from the
Sender's Bank to the Recipient's Bank called a SWIFT message (when it gets
transferred between two SWIFT members (basically all banks with any kind of
international transfer capability)).

There is sometimes a fee to send money taken by YOUR bank, depending on
the status of your account and its benefits. When you want to send money
from First National Savings Bank of Poughkeepsie to a local bank in Germany,
it is easy. However, your FNSBP will go through an intermediary bank (i.e.
FNSBP will outsource all of its foreign transfers to a major money-center bank
like Citi, JPM, BoNY, BoA) and in many cases, there will be an 'intermediary
bank charge' or 'correspondent bank charge' of $10-20. If your account is
with a major money center bank, in many cases there is no intermediary bank
charge. There is a section in most bank transfer forms where you as sender
can check a box and agree to have intermediary bank fees, if any, taken out of
your account. Checking it does NOT guarantee that additional intermediary
bank fees are not taken out of the amount being transferred because the
SWIFT message has a notation added by that check mark, but not all SWIFT
message-processing-banks' computers parse the notations perfectly.

Once the bank transfer is made, the money is out of your account and in your
counterpart's account. While it is not impossible to get money back if a
transaction goes bad and you cannot agree with the seller, you should expect
it will be impossible. You should only send bank transfers if you are
extremely confident that you are not dealing with a bad seller (who is trying to
defraud you, or who will not treat you right should the item not be as
described). However, please note that Sellers selling across borders have the
same fears of Buyers that Buyers may have of Sellers, which is why they may
insist on a bank transfer (because Paypal is structurally set up to allow Buyers
to defraud Sellers but not vice versa).

Elizabeth is right that postal money orders are an excellent low-cost way of
sending money internationally, and domestically in the U.S. If you send them
Priority Mail, you can track the envelope, and separately you put a hold on the
Money Orders by going back to the P.O. and asking them to do so (though
you have less time than with a personal check). And if well-documented and it
is a US recipient Seller, the USPS may make efforts to get your money back
should the Seller commit fraud. Note that not all countries' postal systems
are linked this way. Canada or Australia to many countries just does not work.

Schipo points out the basic problem. If one does not trust anyone, then one
should use credit card for everything. However, using a money order to pay
internationally is no safer than using a bank/wire transfer. Once it's gone, it's
gone. For international transactions, there is substantially less structural
protection against fraud for a buyer unless he uses a credit card. That is
simply the way it is. For the seller, there is zero protection other than having
the cash.