For any startup, gaining traction depends on two things: 1) How many people are you bringing and 2) How many users getting engaged. The first one has a lot to do with marketing, while the second one has everything to do with the product.

Companies launch not over one day, but over a process that can last almost an entire month or maybe more. Phrases like “We got 70k users in 2 days of launch” often have a back-story behind them.

1) Instagram – For instagram, they had Jack Dorsey (founder of Twitter and about 2m followers) back them. So, when they launched, it was fairly easy for them to get their initial users since they needed to get people like Dorsey reach out to their network and the press picked it up pretty quickly.

2) LinkedIn – I was speaking to one of the co-founders of LinkedIn, who was VP of Marketing. He said that initially most of their users were PR based because in the early days, the product was not too viral. LinkedIn took its time to grow compared to other social networks.

3) SkyFire (funding: $41m to date) – Speaking to one of the founders, they launched when the iPhone had just launched and so were a very press friendly story. They also had closed their Series A which enabled them to invest aggressively in PR. So, a lot of their users were PR driven and then word of mouth referrals.

This is pretty interesting since mostly when you hear stories like “we had 70,000 users in 2 days of launch” – a lot of that is paid for or has significant help. It is very rarely viral just from the product.

The effectiveness of PR campaigns is often questioned since a lot of it depends on content, relevance and visibility. However, besides PR, there are other avenues like SEM, SEO, Social etc. which you can tap into for your initial influx of users.

A key point is that after the initial influx of users is established, it is up to you to create a wonderful user experience with your product – create something that is useful and usable to have them stay and give referrals. Instagram grew virally after its initial influx because its users simply loved the product. Similarly, users gained significant value from having a LinkedIn profile, which enabled the network to grow further.

For this reason, before you invest in marketing, you need to keep gathering data, testing and failing in front of a smaller network, probably your own Facebook network till you figure out your product actually works. The product almost will never go viral if you only invite all your Facebook friends, though you will get some very solid data from them using it. Doing this will ensure that when you finally pay for the initial influx of users to come and “launch to the world”, you are better prepared.

Good Luck!