They answer your calls on the second ring at the latest. They respond to your emails within an hour. They send you a nice basket of artisan coffees at the end of the year. They know the names of your kids. Or your dog. Your vendors love you!
If that sounds like you, then you've probably done some of the things on the list below. It's not just approval you're seeking when you treat your vendors well; it's a higher level of attention and an easier route to the solutions you need. Sure, your vendors should take care of all their clients well, but there's taking care of you and then there's taking care of you. Know what we mean?
You Send Detailed Questions
"Why doesn't my site work?" is not nearly as helpful to your web developer as "My home page looks perfect in Mozilla, but there's an extra space at the top and the alignment is off in Chrome." No vendor wants to spend more time than necessary answering a question or troubleshooting a problem for you, even if they bill by the hour. When your questions err on the side of too-much-information, it eliminates a volley of back-and-forth emails or phone calls.
The other reason that this endears you to your vendors is that it proves that you are paying attention. All professionals should want educated customers, and when you give the kind of details in your requests that show you were paying attention, it gives your vendors the reassurance that the issue is real, important, and valid.
You Pay Every Invoice on Time
When the you receive an invoice and -- assuming it is correct -- pay it with no extra nudging required, it may not attract a lot of attention from your vendor, but having it go the other way does attract attention, and obviously not the kind you want. Your network engineer can't bill you for the time it takes to check his records, notice you haven't paid, and re-send you the invoice with a carefully-crafted, polite reminder. He also can't bill you for the time he spent wondering about it, worrying about it, and being frustrated by it -- but those moments do take away from his ability to focus on paid work he needs to do.
If you agreed to the work and the price, and the invoice is correct, just pay it. If not, specify what's wrong ASAP and ask for a corrected invoice, which should still be paid within 30 days of the original (or whatever your agreed-upon timeline is). Just be fair, and your vendor will appreciate it.
You Hold Up Your End of the Timeline
If you are working with a social media expert on a new campaign, and you need to get a high-resolution logo to her by a certain date, failing to do that may very well push off the date by which the campaign will launch. If your vendor does manage to get it launched despite your tardiness, she's likely to have rushed some part of the project that would have been easier had she had what she needed when she needed it. When she has all the information and materials at the right time, she feels confident that she can do a good job for you. When she doesn't have it all when the contract specified it, she's working with a hand tied behind her back. Maybe she's good enough for that -- but maybe not.
Relying on something you need to provide is difficult for all vendors, because it's something they can't control. When you follow the timeline and supply what is expected, it puts the vendor back in control, which makes them feel competent and grateful.
You Remember That Your Developer Is a Person
Sending an email to your vendor at 7 pm on a Friday and being angry when there is no answer at 9:30 am on a Saturday is not likely to end well for either of you. Managing expectations is a big part of any vendor's job in any given project, and if they didn't tell you that they'd be monitoring their email over the weekend, it's reasonable for you to send the message but not reasonable to expect a response right away. When you hope for the ideal but accept the realistic, it makes at least yourvendor strive to impress you. It makes her want to answer you, knowing that you'll be delighted to get a response but not angry if she treats the weekend as a real weekend.
Similarly, your vendor is very grateful when, if she makes a mistake and admits it, takes the blame, and absorbs the cost for it, you remember the things that went well and the graciousness of the responsibility-taking instead of the wrongness of the mistake. She is as human as you are, and she really appreciates it when you can see that too.
Some day, you are going to hit your vendor with a request at the exact same moment as another of his clients. How your vendor chooses which project to take when time is limited is impacted by a number of factors, but your chances of getting first dibs improve by being a responsible, educated, reasonable client.