I bought some BTC on Coinbase last night and had it sent to Poloniex. I know the BTC wallet address was accurate. Its still pending 11 hours later and doesn't show up in the Poloniex deposit/withdrawal history. Any clue on how long BTC transactions are taking?
Typically a bitcoin delivery transaction depends on how many unconfirmed transactions you can see here
https://blockchain.info/unconfirmed-transactionsAnd usually also depends on how much fee you provide for the fee, the greater the fee you give the faster bitcoin delivery process.
Yes, transaction fees matter a lot. The greater the fee is, the faster transaction is. Now a day, I think bitcoins are rising continuously in price so uncountable traders are cashing out their bitcoins or selling them off which is ultimately slowing down the process of transactions.