Thanks for the feedback. We have kept 10kB size limit because it is an entry for 10k apart event. ( A Challenge that asks you to build a compelling web experience that can be delivered in 10kB and works without JavaScript.)

Regarding conversion: We have focused on minimal design which encourages users to click call to action buttons using several techniques described in InstaPages blog & several other sources.

You may read more at: https://github.com/abhas9/ideadeck