Congrats on your launch!
It's hard to say whether 70 members over 7 days is good---it depends on your goals, expectations, and investment. What difference does it make that someone else thinks it's "good" or "bad"?
I personally would be excited, but left wanting more. I would consider the cost of getting those 70 users, and whether that method was repeatable (i.e. how do I get more?). I'd also consider what type of users these are. Are they heavily engaged, evangelical users or one-time users?
In terms of general advice I recommend "Inbound Marketing" by Dharmesh Shah, which gives a lot of helpful ideas for improving traffic/exposure using SEO and social media. It's very likely that you'll need more than 70 users for your website to be sustainable.
I also recommend reading "Four Steps to the Epiphany" by Steven Blank. I say this because from your wording I get the impression that this was a cold launch. How do you know you've built a tool users want to use? How do you know the itinerary purchasing market is large enough to sustain your business? Four Steps is a book about talking to your customers and developing a business without spending too much time and money.