FAQ: How do I set my VAP to invest within the range I want?
While you can set a "value to add" as low as $100 this amount bears no simple relationship to the amount of actual investment each period (that is, new money flowing in). An actual investment could be $0 or as high as the maximum that you set, for example, $2,000. Note too that there are some minimum actual investments determined by the fund prospectus, typically $1,000 first time and $500 subsequently.
If the markets are on a positive trend and your target amount is small it is entirely possible that no actual investment is made for several periods. The reason being that the market is giving you the value added for free. If you want to invest small amounts (for example, $100) on a regular basis you would be better of selecting RSP.