In an effort to find more properties that I didn't need to compete with homeowners for (MLS..), I started reaching out to members in my area that had been doing direct mailing.

My main concern is that the time and effort to market and do the bookings on my own property needs to pay off in a better ROI than a long term investment for the same amount.

I think @Brandon Turner  and @Joshua Dorkin are saving these secrets for an upcoming webinar 

Until then both tenants would be equally responsible for the rent and failure to pay would result in a court order for an eviction.I'll be darned if that first tenant did not put forth the effort to find a replacement for herself but continued to pay her share of the rent for the entire year. 

If this is true, the only thing that would prevent your tenant from moving to the other properties would be the cost and effort of moving.   

Perhaps that will change some day, and I'll want to spend all my efforts hunting for new deals, and will hire out all my work, and that's ok--I'll adjust when the time comes, but for now...I want to get my hands dirty. 

Another term is called time blocking.There is no specific secret sauce.

I have been doing this in USA market, started in 2011, Atlanta and now Detroit marketAs far as Oz markets go its been brilliant in Syd and Melb if you purchased during the beginning of the boom cycle in 2013 and sold out prior to peak. 

This effort certainly helps a newbie to determine whether or not it's worth it to pursue an opportunity to derive a profitable outcome.Additionally, your analysis certain gives credence when it's stated by an active wholesaler who has done multiple deals.

Don't be a secret agent @Joseph Shevy!