Complex sentence: Skiddle has developed a system which allows users to generate their own content which can then be added to their website, which has facilitated the growth of the venues database to around 21,000 venues listed in the UK.
Split into simpler sentences: Skiddle has developed a system which allows users to generate their own content which can then be added to their website. This has facilitated the growth of the venues database to around 21,000 venues listed in the UK.