generally speaking, a common saying is that - if you can't beat the VWAP, you probably don't have much futures as (at least as an institutional ) trader
iow, say that you want to accumulate ABC
over the course of the next 2 weeks
if you can beat the VWAP over the next two weeks with your entries - you need to work on your chops.
VWAP is also a nice way of insuring you get a 'decent" entry price. merely by entering a VWAP order prior to market opening, you can be guaranteed to get the VWAP price by the end of a day.
that's pretty kewl. it's kind of like a dollar cost average thing. instead of thinking you are smarter than the average trader, a VWAP order ensures you get the average entry.