When I get a new customer I always ask where they found out about me. Many are referals but most of the rest found me on Google, so I did some research into advertising with them.
I decided just for fun more than anything else to try Google Adwords, sort
of a pay-per-click system where people searching on my keywords get my
ad rather than just the listings where my website might be on the 3rd or 4th page.
You specify a maximum expenditure, I went for $30. After about 3 weeks I've had 9 people click on my ad for a cost to me of $5.26. Of those, 3 became orders for a total of $160. Not too bad a return on the investment so far. Interestingly, of the 18 keywords I specified all of the clicks so far have been on "acrylic" and "Plexiglas".