Tier2 is supposed to be spammy. It's never 100% safe, but if the tier 1 links are relatively clean then you're running a relatively low risk operation.
thanks for your respond. by the way, any suggestion for tier2 ?
Buy some blasts from the marketplace here....
That's only dangerous if you dont maintain the frequency of your blasts... if you do this and never do any backlinking again you will obviously be penalized.