What are the best marketing options for an on-line children's shop?

For sponsored tweets on Twitter you don't need anyone to do it for you it's pretty simple. Create an account if you dont have one create a tweet keep in mind to use targeted keywords. Then select keywords, users based on interest, gender, geography, device & similarity to existing followers. Run and track your tweets progress with Twitter's analytics.

Try using Google Adwords for Advertisers its one of the best option but not long lasting. You need to focus over value to make your buyers come again and again to buy products from you. However, Adwords will help you to pick edge over the old giants in the industry.

If you do not have an account create one for your business, put up all your products based on category under the boards and promote your pins strategically.

Piqora's conclusion: 1 Pinterest Pin = 2 Site Visits, 6 Pageviews, 78 Cents

Wandering who is Piquora? Well its a Complete Marketing Suite For The Visual Web i.e. Pinterest, Instagram & Tumblr

Facebook offers are effective because you can target the user based on your own criteria. The best part of it is you can do the viewers selection by the gender type, geographical location, interests etc. 

I've seen personally quiet a lot of businesses getting good response from facebook offers. It's beneficial for both clicks and bricks store.

There are many popular affiliate programs sites you can start your own affiliate program, set an attractive commission percentage and then promote it to get affiliate for your business.