true, and all of these risks can be minimized with transparency; if the site shows their bankroll at all times as well as proof of funds, investors can see for themselves weather or not the site's investment system is legitimate or not. i believe the lack of this transparency was why dadice decided to halt their investment option as well
Dicebitco.in offered exactly that but it still ended up making its investors lose money. It offered proof of funds and the size of the bankroll was always shown on the upper left corner of the site:
Proof of funds and an already starting bankroll of 3000 7500+ BTCs! Yes, SEVEN thousands five hundred. . Our COLD wallet --> https://blockchain.info/address/19tQNCrmaW6EADfJrtBaRixRkPyVrvb6yk
Just passed 1k+ Bets in less than 3h O_o
Quote from an article on the site's demise:
Quote from: CoinTelegraph
Since the beginning of the authorship of this article, DiceBitco.in owners manl and gerry have stopped responding to users on Bitcointalk and a player, going by the name mateo, has continually placed bets with a near perfect win ratio, emptying the site and stealing the entireity of investor funds.
Link: http://cointelegraph.com/news/112470/dicebitcoin-accused-of-cheating-players