In my opinion... No ....build strong back links for reputable relevant sites ,that's the way to go......
The question is hoe long you will keep buying traffic. So best is to build your own traffic by good content and with better promotion of your sites.
depending on where you are buying the traffic from. if it is PPC traffic, then it sure helps. but if you are buying bulk traffic form some traffic broker, then most of the times its a waste. ask youself a question. if you had the traffic that converts, would you sell that traffic to someone else for cheap or would you convert the traffic yourself to make larger profit? there are big scams going on with this business where lot of crooks use bots to send you hits using proxy list. if you look at your analytics, you will see all unique visitors but they are nothing but proxy hits with ZERO conversion so be careful
You have to ask yourself: "for what i need traffic?" Than you can answer the question if you should buy traffic and where.