It would be a bad idea to increase frequency, first if within that timeframe one of the players get lucky enough to win more than the house edge in this case the house lose its advantage (applicable to dice game), second for player who is like ben which only play on sport betting and you cant force it to have more events in a short timeframe, third you have to think where is the fund for them to play, may be trading and to finish a trade it takes at least one or two weeks to get out in profit (thus having some spare coins for gambling).
The site makes profit from people betting. They don't care if certain people win, and if someone bets a lot and ends up winning, they might come back and lose it all the next day (even without a wager competition). There are people who play only on the last day and we don't see sites making it an issue.
For sports, a shorter phase might be helpful for sports players as dice players would have a smaller period for them to bet. For example, if we had a one day competition and there were many events on that day, a sports player would be able to wager a lot. If we spread it out to a week, there might not be another day with many events until next week so the sports player basically plays for 1 day vs dice players who could play for the whole week.
