Lesson#1-Our customers don't always know what a "list" is. Or what an "autoresponder" is, or what a "double opt-in" is, or why they need to "confirm" their "subscription" on "AWeber" to my "list". Terminology is important.
Lesson#2-Our customers don't always know what a "PDF" is, or an "eBook", or a "digital file" or an "electronic download" or even a "downloadable file". While I'm off selling my "eBook" to many folks on my list and thinking I'm a pretty smart guy, I get questions from my list like "What will the cost be to ship the book to Malta?" Duh, I'm an idiot sometimes.
Lesson#3-Our customers don't always know what a "membership" is. I sometimes assume they know there's a monthly fee and they don't get a "real" membership card mailed to them, and they can't sign their friends up, etc. While I think I've explained everything, I get the occasional "what's does "content" mean?" or "what does "timed delivery" mean?". Ahhh...back to the drawing board.
Lesson#4-Our customers don't always know that a PayPal button can be used even if they don't have a PayPal account. Yes Mister subscriber, credit cards, debit cards work to.
Lesson#5-Our customers are sometimes nervous (Spam) about clicking ridiculously long links from AWeber, or tinyurl/bit.ly/cli.gs type links. It kills click-throughs. Note to self - use domain names they are familiar with and do redirects.
Lesson#6-Our customers don't speak the same language we do. Colloquial terms, certain humor, references to domestic current events, etc. are many times lost on our customers. Their holidays are different too.
Lesson#7-Our customers don't all live in my time zone. I've got to stop sending emails that talk about "tonight" when it's already night time there. And my tomorrow might already be their today!
Lesson#8-Our customers don't always transact in US dollars. The exchange rate for some countries makes our $7/$17 products unaffordable. Would I be willing to sell that $17 product for $4 in certain countries, or maybe not sell in that country at all?
Lesson#9-Our customers don't always have a high-speed Internet connection. 32/50/63MB downloads don't work on dial-up. Break those downloads into manageable chunks.
Lesson#10-Our customers don't always have a Zip utility and know how to use it, or run the full Microsoft Office suite, or have Adobe Reader loaded, or all use Internet Explorer.
Bonus Lesson-Our customers don't always tell us what's on their minds. Why didn't they buy? Don't they trust me? The product's great and dirt cheap, what's the issue? I need to communicate more and find out what they are thinking, do surveys, split test more, and try new subjects/headlines.
So, what lessons have you learned outside of the make money/IM niche? Please share.