He said they laughed at first, but then later, after   these types of houses, they would send more houses his way.He said that the trick was to have the closing on the day rent was due from tenant, and I think he said he'd have $1,000 earnest money for the closing too.

The trick is: make sure EVERY property you buy with these strategies is a no-brainer bargain, so that you'll continue having significant equity even with higher borrowings!

surprisingly frequently.

However, anything more frequently that every 10-14 days with more than three mailings seems a bit desperate to me. 

They will know who frequents the store, how they manage their accounts and the types of work they do.

Any other tips or tricks of the trade?

I'm relatively new to the real estate business and eager to learn the tricks of the trade.

Also, never try tricking the bank about costs/deposits!

Tons of rentals, thousands of agents working an uber-competitive market, many of them using tactics and tricks that contribute to the bad reputation we often get.

Would you guy by concerned of such a trick?