Selling beats online is like watching paint dry. Most people on the net are looking to get theirs for either very cheap or free. Soundclick is a very good way to post your whole arsenal on the web for people you meet locally. That's how you can spread word around.
What I did in the past (I haven't sold too many beats lately because I've been working on HM and my solo album yadayadayada) is put about 20 full beats (or about 70 or so samples ranging from 1:30 to 2 min flat) on a demo CD that you bring with you to prospective clients. If the clients are homies then I bring the full beat CD so that they can hear changeups and what not. If not, I bring the sample CD with me so in the off case I do get into some shady shit, they're not getting full beats on that CD.
None the less, have at least 1/4th of your beats available on the CD to listen to in a sample format. That way if they're feeling your work, you can give them a business card (I strongly suggest using a business card, it's more professional than just writing your site down and you can get them really cheap for the quantity). When they see your business card, it'll have contact info and your site on it. That way, they'll want to check your site out to see what they didn't catch in the initial interview.
Also, if you have artists that you're tight with, work out deals with them. Let them have a free beat for every 3 people that they bring you who buys a beat from you. Musicians love stuff for free so you can make them do some of the hustling for you and bring you new clientele. Hell, I have artists who put out good word for me at MC battles and around the underground network simply because I promised to put in a little work for them whether it's cross-promotion, a discount on buying beats, or a beat outright for free (it still has paperwork though don't sleep on that).
A little time, a little drive, a little hustle, and a little magic and you can make that happen homie.
Fiev.