hotels and outcalls
Congratulations on cracking the hotel market! There can be a great deal of money to be made, particularly with the Mayo Clinic visitors! Bear in mind, business travelers are more prone to ask for a female therapist, should the hotel contact bother to ask for a preference. You might want to find a partner.
Let me address your last question first. The hotel personnel - particularly concierge - expect something for the referral. Preferably cash, 20 - 35% of your fee. You should price accordingly. 50% over a visit to your spa would be appropriate to cover the kick-back and your time and trouble. Trying to give free services would be better for you, but other therapists will offer them cash & sometimes even a higher % - so their loyalty is almost non-existent.
One of the dirty little secrets of the hotel industry is that all outside services - limos, florists, massage, even top restaurants - all pay off the concierge for the referral. This means higher prices to the guests, who usually end up tipping the concierge for pulling these rabbits out of his hat! Guests are oblivious to this practice, and the hotel GMs either are, or choose to ignore it.
Which would leads us to your first question - do contact the hotel, but be careful who you address. First of all, corporate chains, and Marriott is about as corporate as you get, are often squeamish about massage therapy happening in their hotels. Often, you not only have to name the property as an additional insured on your professional liability policy (not a big deal) but you have to show proof of worker's comp insurance, sign a waiver, etc., etc.
If you elevate the issue beyond the level of the concierge, you risk the Guest Services Manager or GM being indignant over the existing practice of cash commissions, not just for massages, they will see the bigger picture of all services. You will have just killed the concierge's golden-egg laying goose. Chances of him ever calling you are somewhere south of 0. Unless the GM is so grateful for this insight, that he requires the hotel to use you exclusively (which is tough to fulfill if you are sole practioner, and male to boot) and keep the commission for the hotel. Addressing management can be the nuclear option, but has a high pay off. Where we have a contract with the GM, we have signs in each guest room, signs in the fitness center, a weekend romance package featuring a massage, chair work for their corporate groups and meetings, puts us on their website etc. They do 3 - 4x the volume of a concierge-based relationship.
If you go for the GM and try to get his attention with commissions for the hotel (and it is not insignificant, a 4 star hotel should do at least one massage per room, per year; you do the math!), you run the risk they will not read your letter in depth and just pass it on to the concierge who makes those kinds of decisions. The concierge then sees you went over his head and tried to cut him out.
If you stay at the concierge/front desk agent level, you are limited with them as gatekeeper. They only respond to requests, and if guests don't see a spa, they assume massage is not available and only the spa savvy traveler bothers to ask. The requests they do get might get spread around to other therapists out of some misguided sense of fairness. The fact you are reliable, professional, etc. etc. counts for very little if another therapist drops off a business card, complains about how broke they are, offers a higher %, what have you. If they call you and you are unavailable, but find someone else to do it, chance are they will call the new person first the next time they get a request.
What have you done for me lately is their modus operandi, since a missed appointment means a missed commission and a missed tip for them.
They don't give out business cards to guests & that would allow the guest to make their own arrangements and cut them out of the equation. They usually aren't allowed to hand out fliers or get them in the rooms.
Good luck with whatever path you take!