JM wrote in comments: Should I ever get published, I would like to save myself, and those others interested, time and money in the marketing department by not trudging down paths where the investment isn't worth the return.
I suspect JM is a writer after my own heart. So let's tackle this list of questions:
Specifically, what methods work and what methods don't work for marketing your novel, or, by order of increasing effectiveness, what methods have you used to market your novels?
Traditional marketing methods, such as widgets, booksignings, conference appearances, mail-outs and print advertising are the least effective. Newer marketing such as websites, online interviews, articles and weblogs are better and, depending on the quality and appeal involved, can be terrific.
M.J. Rose's theory of getting big time media attention, particularly the kind that thrives on scandal, is likely the best marketing, but it can also be the worst. I tried most of the traditional methods for my first novel, and the newer stuff for the first Darkyn book, but I only kept up a small web site for all the books in between.
In your discussions with your published cronies, what are the similarities and differences in the effectiveness of their marketing efforts when compared to yours?
I don't really have any published cronies. My best friend is an author, but we talk about the creative side of work almost exclusively. I sometimes offer advice upon request, but I rarely if ever talk about my stuff with anyone else.
What methods have other published authors reported to you as successful that you haven't tried yet?
None so far.
How helpful were your publishers in marketing your novels?
My publishers used to take out print ads in the trades, and send out the usual amount of review copies. To my knowledge, that's all the marketing they've ever done for me. Print ads do very little for a book, and you all already know my opinion of reviewers.
What promises did your publishers make to you regarding the marketing of your novels and how many of those promises did they keep?
My publishers never promised me anything on marketing in writing. Of the half-dozen verbal promises that were made, only one was kept. I never believe anything unless it's in writing.
Should I get an agent before circulating my first novel to editors/publishers?
People are going to debate this forever. In today's market, a decent agent** will not take you on without a book offer from a major publisher in hand. I'd recommend nailing an offer first, then go agent-hunting.
What's your take on online critique groups and/or critique groups in general?
They don't work for me, but I know many other writers depend on them and enjoy them. If they help you, great. If they mess with you, dump them.
Assuming you had a day job, how long after you first became published did you quit your day job?
I had retired from business and was a ten-year veteran housewife when I got published. I'm still a housewife, and aside from writing, taking care of the people I love is not something I'm likely to quit doing.
If you haven't already done so, if you could only give us one bit of advice about the business of writing and selling books, what would that be?
Oh, no pressure . . . okay: Somewhere in the midst of all the important marketing, strategizing, planning, researching and obsessing, try to write some books. I know, it's a completely radical idea, but the more you write, the better a writer you become, and the more likely you are to sell.
**Important Contrasting Opinion: Literary agent Miriam Kriss responded with the following in comments: I sold someone out of the slush pile last week to a major publisher and I'd like to think I'm more than decent. Any agent will take you on when there's money on the table, but only an agent who will really fight for you will take you on out of the slush. That being said, if you have an offer in hand, be picky. Find an agent who will really share your vision of your career and your brand and help you build both. Don't panic and take the first person who says yes. The offer won't evaporate if you take a week or so to decide.
You can read more about Ms. Kriss in an interview she did here.