In many cases it's the client that holds all the cards and determines whether or not a deal closes.

When my handyman came to the property, I would give him the list and a credit card, and he would spend the afternoon driving back and forth to Home Depot.

It's very common to have a credit card used during a free-trial sign up.

I manage all vendor payments via credit card with dedicated credit cards via Baselane for recurring vendors like landscapers, cleaners and hot tub maintenance.

I am sending out 600 cards a month.

It impacts the cost of everything...food, shelter, transportation, health, recreation, labor. 

Now that I own rentals my debt cycles with winter fuel and sometimes remodels being put on a credit card.

I would like to keep the number (biz cards etc...) but I am not stuck to it.

. - Conference ticket/registration- Hotel Room- Flight + other transportation- Meals on-site, etcConference experience costs are much more than just the registration fee. 

Under the IRS rules, a person  qualifies as a real estate professional if: (1) more than one-half of the personal services the taxpayer performs in trades or businesses during the tax year are in real property trades or businesses in which the taxpayer materially participates, AND.....(2) hours spent providing personal services in real property trades or businesses in which the taxpayer materially participates total more than 750 during the tax year.Like @Greg Scott and @Russell Brazil mentioned above, I don't believe that you would qualify as a REPS, but if you are going to try it, make sure you document it very well (i.e. with some kind of proof, like time cards, mileage forms, and/or receipts, etc.) so that just in case you do get audited, you at least have something to provide to the IRS agent.