Most times you probably will never hear anything back, especially if you're new, and especially if you are sending proposals to 'new' clients ('payment method not verified'). Most posts from 'new' clients are never filled (probably 95%+), and are often just 'posted' and then abandoned and are usually being posted by somebody just 'testing out' the site or just 'playing around' to see what happens, or 'checking to see' if they can find somebody to build a whole smart phone app for $0.50 - when they can't, they just abandon whatever they posted and split.
A very small handful of 'new' clients are serious and actually turn into paying clients, but the vast majority are not: Just scammers and folks 'playing around' on the job boards. So, if you submit a proposal to a brand 'new' client you should pretty much expect nothing to come of it, send it off if you wish or don't, but either way - forget about it and count the connects wasted.
For the real clients with a substantial hiring history & money spent, it depends on the industry and how much competition you have (how many proposals got submitted for the same job). Anything over 15 proposals, and you'll most likely never hear anything back unless you were among the very first to apply. Also, if you send a proposal after the job post says they are already 'intervieiwing' people, you'll likely never hear anything back. Usually a waste of connects. I never submit a proposal if the job post says they've 'hired' somebody. Waste of connects
If it's a really good 'match' I normally hear something back within minutes/hours or at least within 24 hours. Sometimes a couple days if it's over a weekend or holiday (i.e., you send a proposal Friday or Saturday and might not hear back until Monday). I've had a few clients decide to 'respond' weeks and months later after I'd forgotten about the proposal and was no longer interested or available anymore - I usually just withdraw the proposal when a client 'pops up' that late and after-the-fact.
One suggestion I have for you that may help you stand out: If you have specialized experience dealing with the freight, shipping, logistic industry, you may want to create what's called a 'specialized' profile highlight those particular skills and experience. You're offering services in a crowd/competitive field, and client's often favor freelancers that have specialized knowledge of their industry over freelancers that don't. i.e. a Freight/Shipping business that needs a data analyst will likely prefer a data analyst from the Freight field over one who is not.
