Hi buying traffic is may good for new websites but you have to do seo to gain traffic without paying for that.
If you mean PPC like ADwords and stuff if you can aford it is ok If you reffer to Traffic ofers from x and y that's pure crap i won't waste money on that ...
While i really liked adwords for me buying traffic and banners(based on cpm) worked the best.My old website (doesn't exist today... ) reached a crazy alexa of 18k to 25k !! .Web traffic worked but needed to be bought for a long amount of time.The thing which got me most leads was buying banners in websites and the traffic solidified the gains i guess?
Paid traffic sometimes works and sometimes don't. I am more fan of the organic traffic and SEO, because it's free and you can learn a lot
i have bought traffic to one of my sites It is adsense safe, but I didnt make much with it - it was human traffic. Increased my alexa and did help with google rank - overall I am happy with the results and will buy traffic again IF its from a reputable person and adsense safe
Black hat is always an option nevertheless unless you really know what you're doing stay far far far away from it .
Organic traffic has much higher conversion rates than bought traffic. Organic traffic is your typical pull marketing technique, while paid traffic is your typical push marketing technique. Getting people to your site that are drawn to it because they have an interest in what it offers is going to work every time over someone you pay to get there that may or may not really be searching for what you have to offer.
I do not know why people praise Facebook ads. My lowest limit was $1.00 per click and I would get about two clicks per hour with no profit until my ad was used up at the end of the month. PPC is obsolete because once everyone jumps on board the cost per click is so expensive that you will not gain any profit. About eight years ago when you could get visits for $0.15 cents totaling about $100 per month than that was worth it but not now.
PPC is the best way to spend your money so long as you get uyour bids right, then SEO on the back of the conversion rates you see for certain kws.