Running an online business doesn't always need to be about the exchange of money for services, in fact if we think about it like that, business would seem almost entirely cold and calculated, which I don't think it is or should be. So here are a few things you can do for your clients that will make a difference to their working environment with you, and the best things is, they won't cost a penny.
Take an interest.
Taking an interest in your client is very important, business is business yes, but in your interactions open and close the business-talk with greetings... "How are you?" "How is your day going?" "Did you see The Big Bang Theory last night?" "Did you enjoy your holiday?" etc... you get the idea. Let them know you care about more that just their business by taking a general interest. You know how nice it is when people take an interest in you, right?
Mark special occasions.
With Facebook and Skype these days it's fairly easy to obtain a birthday date, or through conversation when someone mentions an anniversary, make a note anytime you get wind of a client's special occasion, and give it a mention, or send a personal email to wish them well.
Be emotive in your responses.
Just because we're working in a digital environment doesn't meant to say we can't make expressions, or communicate feeling through keystrokes. For example...
:-) - You're smiling
! - You're excited
!!!!! - You're really excited
:-/ - You're confused
:-( - You're concerned
:-D - You think that's hilarious
Saw this and thought of you.
Do you ever come across blog posts, articles, funny quotes, images on Pinterest or status updates such as tweets of Facebook updates that could be applicable to your client? Why not share a "saw this and thought of you" with them? @reply them on Twitter, send them a link in an email, send a direct message, share something on Facebook or tag them in an image. The "saw this and thought of you" thing is a gesture, a very nice gesture actually.
Share their stuff.
If I have been working with a client on a project, or I've enjoyed reading one of their articles and find it could fit in well with a newsletter, blog post or social media avenue, I'll share it. I'm happy to help my clients along by giving them a mention or retweeting their posts. I work with a variety of people, many of them are experts in their field, and I enjoy taking an active interest in what they're doing, what they have to teach me, and passing these things along.
Basically in other words, think about your clients, try to do at least one small thing a day or a week for them, and these little acts of humanity can go a long way to establishing an excellent relationship!
Tell them a joke.
Just because it might make them smile, and smiling is good :-)