I am going to start a marketing campaign sending letters to potential sellers indicating that I would be interested in buying their home. 

It also, to a greater extent than many other types of REI, requires well thought out and highly scrutinized marketing campaigns.

Try mailing campaigns.5.

We would also run a text campaign, some SEO and some targeted mail.

I work in sales in my W2 so pretty well versed in how to build sequences, outreach campaigns, scripts, etc. 

We send out emails, newsletters, campaigns etc. through the entire thing.

One option - (looks like you've already taken this route) - Shack up with a local investor-minded realtor, they will be more than happy to set you up on a specific, filtered investment property drip campaign. 

However, I'd like to think I have several "sticks in the fire" to find deals including: MLS, commercial brokers like CBRE and Marcus and Millichap, boutique brokerages houses, off-market campaigns via email or direct mail, wholesalers, turn key operators, etc..

While it’s possible engaging in one of these programs can shorten the time required to become a “power” agent considerably, it also may be a gigantic waste of money if marketing efforts are engaged without waiting for the all important test results.One popular career tract being offered in collegiate business programs across the world right now is marketing data analytics - analyzing the results of test marketing campaigns and applying/interpreting these results to form an effective and profitable marketing program.The other choice is to engage one of the many companies that will set up a generic real estate agency website for you, with the usual stock photos as well as MLS feed, create a blog and tie it to the new website, and start posting information and answering questions are various social media sites.After getting your feet wet, you can purchase services such as SEO, or a PPC campaign, on a a la charge basis, and track the results using one of many analytical programs available online.

🗺️Where to find off-market properties:- InvestorLift and any other wholesale aggregator- Make connections with local wholesalers at REI meetups or on Bigger Pockets- Most investor-focused brokers are plugged in with wholesalers and do their own monthly direct-mail campaigns and cold-calling.