What Is a Good Approach for a Lead Nurturing Campaign And How Do I Get Started?

I hear this question quite a bit. The key for me has been to think of the buyer's process of buying, instead of the company's process of selling. I break down the customer's buying cycle into 4 stages and try to think of the types of content or messages that would work well at each stage:

-- Unaware: You need to catch the attention of buyers who don't know you or your product yet, so your content needs to be interruptive. This is where to use catchy campaigns in media that will reach new targets.
-- Tentative: The buyer is doing research, but is resistant to engagement or commitment. You can help the buyer, and boost credibility by providing content that is educational. Technical white papers, research reports, and product brochures and demos work well here.
-- Engaged: Once the buyer is in contact with your sales force, marketing can help nurture the opportunity by supporting sales with content that validates the buyer's decision. This is often where case studies come in.
-- Invested: For most companies, the customer is still also a prospect for future sales. Make customers feel like members of your exclusive club to build loyalty.

Marketing automation systems are extremely useful for managing the ways your buyers use this content. The specific types of content you use in each phase depends on your industry, and buyer personas will help you to develop pieces that appeal to the people you want to reach.

This is a broad question, and I'll be glad to elaborate on it more specifically if you have follow-up questions.

I love that angle from Paul.
I've been going with a person's 'digital rapport' with your brand:
Stranger Prospect Customer Fan Ambassador

Where a Stranger is unaware, Prospect is Tentative Customer has been or is engaged Fan is very engaged and Ambassador is so engaged that they practical sell for you.

Anyone who gets to your site, usual through SEO and PPC would be strangers. Of course you will make is as easy as possible for them to spend money with dedicated landing page etc. and convert to customers, but those who are tentative may not buy but will sign-up for emails, so make that easy. then use targeted emails to the signed-up prospects to convert them to customer.
Once they are customers, keep the experience great and nurture them into fans with email and social media interactions, feedback and offers etc.
Turning fans to ambassadors is can take more than just digital interaction depending on your brand and business model. Some may need face to face interaction to really nurture that rapport and turn it into a relationship with the personal touch.

This often takes more than just one bit of software to get right although some might claim to provide it.

You'll need decent tracking system for each inter\action, email, twitter, facebook, seo etc with the ability to get that data into a central spot, like a good CRM or data warehouse where you can then put people into the right segments and send them the relevant content.

To get started email is the main spot for interactions to start with because you can track individuals easily. To then match that up to their twitter id and even facebook profile is sometimes a big step and if you are B2C it's rarely worth the effort.
However, the ability to track people through you web-site often is, so have a web analytics platform that can track individuals, from emails at least, will help.

If you have on-line purchases this will definitely need to be linkable to the email activity.

Obviously a lot of models also include telephone and tradeshow interactions which will need to get into a CRM and be matched against the email activity.

Once some of that is in place, you really only need to update people's status on the ladder monthly to start with, so you know how to best target people.

A good place to start is how long since they last opened an email and how long since they last spent with you.

I was about to come with my opinion on this, but want to say that Paul and Andy's answers were REALLY good.

Here is what I have to say: Don't do lead nurturing CAMPAIGNS.
Instead, create an always-on Lead Nurturing Program. To me, campaigns have a definite start and a definite finish. You can run campaigns within your lead nurturing plan, but don't think you can just do a "lead nurturing campaign" and be successful.

Lead nurturing takes time to perfect and optimize.

The best approach to lead nurturing is to work out first what you want out of it.

For most B2B companies, lead generation and qualification is about intelligence gathering, not automation.

So ask yourself some questions:
Do you want to find out where in the organisation your lead sits and find out the details for the other people likely to be involved in the decision so you can nurture them?
How can you use your contact to evangelise throughout the organisation and what content do you need to create for them to spread?
What surveys do I need to do to more closely define their requirements, find out who else they are considering and what their key decision criteria are? How do I maximise response?
Consider your segmentation and how to create a white list of clients in each sector you want to be in with - and how to set up an alert when any of these companies gets involved?
Is it for a small part of a large organisation?
Is it global, country-wide or local?
What is the problem they are trying to solve? Have they made the right decision in coming to you?

There is a host of data which will stop you wasting time on non-leads and researchers and will give your sales team an edge. Knowledge is power. So work out how you get that information easily and co-operatively from your prospect.

Then work out what your prospect wants out of it. He/she wants to evaluate your solution. So you need to work out:
How many steps are in their buying process?
What information do they need at each stage?
What are the key things to understand?
What are the technical details (not necessarily for them but somebody needs to know)?
What are the killer features?
What are the killer features they'll be told about from elsewhere - and why are yours more important?
How easy is it?
How safe is making this decision?
Who else has done it (ideally someone like me)?
Is it right for my industry?

There's a host more but you get what I'm on about. All of these need to be addressed - and all of them are an opportunity to put your product or company above the others.

Allow for the fact that different people want to connect in different ways.
Some will be happy with email - most won't.
Some will like video - most won't.
Some will want to ask their own questions.
Some will be happy to give you information to help you show them what is right for them - some won't.
Some will be happy for you to talk to all the people involved in the decision - some will want everything to go through them.

You probably don't have the resources to satisfy all of these. So do some research or even some trials - find where the 80;20 rule applies - 80% of responses for 20% of the effort.