I have set up the BrightTalk connector for our Marketo instance, but it seems like it is only useful per each webinar event and not on a regular basis to auto import channel subscribers. Daily we have an influx of webinar channel subscribers but they do not necessarily watch a particular recorded webinar of ours - they may have downloaded a whitepaper or other content we host on our channel. So the question is, can I have these channel subscribers auto imported to Marketo if they do not apply to a specific webinar event I have previously set up in Marketo?