Windice might become the second Bustadice, and it might become great with supports from community.
Together, Windice community and the team can make it great in dicing area. Promotions that last long and have good post quality from participants have better ability to catch attention of potential riders, who later might join WinDice site to play.
Comparison with those OG's of dice sites, I don't think it should be done. For now, WinDice is still on the phase of building it's own empire while those established ones you have mentioned has their own too. There's a tough competition to the dice gambling community but WinDice is on its way to the top too and don't want to let itself at end of the line. The promotion and campaign held by WinDice will continue because it's very effective and just like what other casinos do, they never get tired of promotions.
For building the trust and getting more players, they should really took some more actions like better promotions and giveaways. These things must be done in order to gain community and slowly they can improve their game as well to make people believe on what windice going to achieve. By getting slowly on each milestone will gain more trust that they need