We have summarized the updates timeline of ECB since it's initially released.(There are 20 versions!) This is the list for iOS platform excluding other platforms. Feel feel to predict what date will the next major version update v2.5 be launched?
2.32 May 24, 2015
2.30 May 21, 2015
2.24 Mar 21, 2015
2.20 Mar 04, 2015
2.11 Dec 02, 2014
2.1 Nov 17, 2014
2.0 Sep 11, 2014
1.91 Aug 04, 2014
1.90 Jul 21, 2014
1.80 May 27, 2014
1.70 Mar 15, 2014
1.6.1 Jan 09, 2014
1.60 Jan 02, 2014
1.51 Nov 08, 2013
1.5 Nov 06, 2013
1.4 Sep 28, 2013
1.3 Jul 31, 2013
1.2 May 27, 2013
1.1 Mar 29, 2013
1.0 Jan 28, 2013
That sounds really good. Many new players enjoy playing hardcore mode. Maybe you can make new quests but instead of putting them at the very end of the quests go back and squeeze them in between the current quests. It's unlikely that some new llayers will make it all the way past the current quests to play the future quests without quite some time and strong effort.
Another idea could be a "campaign a day." Every day there is a daily campaign worth 20 rubies. One day can be pro next day can be hardcore. Many people enjoy the campaign mode and the campaign mode is the best way to learn the game so this could be interesting. Would also let some of those new players do hardcore mode campaigns.