Tying your entire professional reputation to a single website is an unbelievably bad idea. Not only does it let companies get away with what Freelance et al are doing, but it keeps you making artificially low rates. Contribute to open source, network in your community and online, and do pro bono work for charities. If you're good, your reputation will rise and your business will not have a single point of failure.
Importantly: it is both not true that your reputation will necessarily be improved by working for charities/contributing to OSS, and not necessary that one has "a reputation" to successfully get consulting gigs.
To get a consulting gig, you need to a) identify a person who has the authority to say yes to a consulting gig, b) convince them to say yes. Even if you have a reputation, you don't get to skip these steps. Reputation as being among the top in the field will get you more inbound leads, but you'll still have to sift down to people who can actually say yes to gigs, and then sell them.
How do you think your average accountant sells accounting services? By having a reputation as being one of the best accountants available for hire? No. They meet with business owners, winnow down to the ones who have money and problems with it, and then say that they'll trade solutions to problems for money.
