Do contacting companies and making cold calls and send emails to companies has been something useful to generate traffic ? Do these “Fiverr promotion” gigs actually work ? What do you guys recommend ?
You are talking about a category of services which has literally thousands of different gigs and sellers. It would be impossible to say “yes” or “no” about the entire category. I recommend finding your target market and then deciding on the best way to target them. If you are targeting kids, then an email campaign will be ineffective as most don’t use email - but a social shout-out might work better.
If you are aiming towards students then perhaps a smart video promoted on related channels should work. Etc.
If you want me to buy from you, never send a spam email and just prove you are competent in what you do, then I will find you.