You're presumably the expert on this subject, so just take this as an example: let's say your target audience spends a lot of time grant-writing. Aha! You, being the expert on their needs, might also know a lot about grant-writing, maybe specific with grant-writing-for-physical-goods-purchases. Why don't you collect your expertise about that subject in, say, a 15-page report?

Then, instead of "Please give me your email address because that would help me a lot", you'd say "Do you have a problem grant-writing? Of course you do. I'll send you a free copy of my 15-page report on grant writing, including these 3 tips which will save you time/stress and make it more likely that your grant is successful. Where should I send your report? [email address] [Get My Free Report]"

You make it clear on this page that, in addition to the report, you'll be sending them other stuff that they'll find valuable, and if they don't, they can stop receiving it at any time.

Other stuff:

1) AppSumo will tell you that, for your first 1000 customers, your issue is less "How do I collect a large number of email addresses?" and more "How do I bang down the door of 1,000 people in this niche to have meaningful conversations with them?" You can literally justify putting your email signup on an iPad and going door-to-door or conference-to-conference getting signups at this point, just to have a better understanding of where your target customer is at.

2) In specific response to Q1, at this stage, any landing page template off the shelf is better than what you have now, and paying a developer is a poor use of your limited resources. You can hook together e.g. Unbounce or e.g. any landing page template on ThemeForest.net to e.g. Mailchimp in under 15 minutes, even with no special development skill.

3) In direct response to your Q2, this question is "How do I do marketing?", and that is outside the scope of an HN comment. Don't worry about that right now. Get the incentive written, get the landing page up, and get things to the point where you can take someone out to coffee and browbeat them into signing up on the spot. If you cannot convince someone to sign up for your mailing list while you're looking them in the eye you will never convince 10,000 people to sign up for your mailing list just from looking at your landing page.

    a)made you lots of money
    b) saved you lots of money and time

If that's the case, there is no reason you need to hire a developer to build this. If you want to MVP this and just test something, you can throw up a landing page with Premise 2.0 software from copyblogger. I've written a tutorial on this here - http://socialmouths.com/blog/2012/04/17/premise-2-0/ . It's almost offensively simple to do and you should be able to have a decent opt-in page up and running in 20 minutes.

If you're looking to collect emails, I would integrate it with MailChimp (Aweber is better, but MailChimp is free for your first 2000 contacts).

As for marketing, we'd have to know more about what you're interested in selling eventually to these customers as your incentives for getting them to sign up will vary based on wherever their interest should be targeted.

Hope that helps.

At least with Tiny Letter you're ready to go to send emails once the emails are collected.

Or you can create a basic page using Google Sites and embed the tinyletter code on it to collect the email addresses. I've done something similar here: http://goo.gl/OyAXK (you can also embed a twitter widget on the page too as I've done to publish updates to the page from twitter)

- just find organizations, and specifically people in those organizations who can push out your message. Also go to online forums and post there. In your postings, have your webpage as your signature. Try yahoo and google groups.

Q2: Simple google hack gives you easily email addresses from forums and other websites where this niche group shares their email address publicly. Query something like this "@gmail.com site:mmorpg.com" the email address domain works so that it will search for email addresses from that email provider and the site keyword specifies the website where you want to find the email addresses.

Anyway with a landing page you should use google adwords for advertising campaign instead of trying to spam users to get their email address which you already have.

B) Explain exactly why the customer should fill in the email. I don't like bribing the customer with some other unrelated thing, like a white paper because people who want the whitepaper just want the white paper. They might not be your actual customers. Instead I would honestly say (example) "Do you want awesome deals on physics and astronomy instruments? Well we're going to find deals for you and send an email every month."

C - Niche products need niche sales strategy. Find out where your customers spend time and figure out how you can get in to meet people. Explain what you can do for them and ask for an email on the spot.