One interesting legal aspect to gambling is whether it should be considered a game of skill. There are states in america which ban gambling but allow games of skill. The distinction between the two can represent a fine line determining whether something is legal or illegal in some states. Recently there was a case where fantasy sports platforms like fanduel and draftkings claimed they were a game of skill but were said to be gambling by some US states and banned on a state wide level.
Merging gambling with games of skill could be one area dice sites could focus on. An example of this could be including the results of mini games in dick win/loss algorithms. For example, let's say there was a pacman mini game. If someone scored higher than 1,000 points their odds for winning could increase and if they scored below 500 points, their odds could flip in the opposite direction. Similar paradigms could bump web platform dice from being hard gambling to representing something more similar to a game of skill, which could allow it to be more widely adopted(and also increase appeal on the basis of originality).
Another area that comes to mind is internet dice's "provably fair" concept. Devising a better, more transparent method of ensuring fairness could a long way towards attracting customers, many of whom may not know what provably fair is much less the details of how its supposed to work.