He wants someone to do the research – something I’d love to see it too.
I personally don’t think it’s as simple as a full feed or partial feed thing that determine’s a blog’s feed subscriber count. It definitely can help though. For example here at ProBlogger when I moved to full feeds my feed subscribers did increase by 10-20% in the next month (although onsite traffic decreased a little).
However on Digital Photography School I’ve managed to get my subscriber count up to over 4000 in 9 months using partial feeds. Having said that – I’m close to moving it to full feeds also as I’m keen to see if I can boost it further.
Ultimately the biggest factor in getting people to subscribe to your feed is producing quality content that people don’t want to miss.
I’ve said here before that I’m still torn on whether to recommend full feeds or partial feeds. I think it depends upon a number of factors including the topic, the style of posting, how much time you have in dealing with content theft and whether you care or not if people steal your content.
Still – if someone does a study into full vs partial feeds I’d love to read it!