Most online advertising networks have an option by which you can withhold the payment  till it reaches a certain amount. This option is useful if the payment is sent by check in US$ and you live in a foreign country.

Many banks charge a fixed amount for converting a foreign currency check to local currency and this amount can be as high as $7 per check irrespective of the amount. So if you have a small check, most of the payment will be wasted in bank charges. The disadvantages of holding payment is that the company may no longer exist after some time, and you may lose your money.