Hello Taysir,
I don't like the suggestion of trying to rank for similar searches. That smells like "bait and switch", and would probably lead to poor user-engagement metrics, which would eventually harm your rankings across the board.
Creating demand for new products and services is always a challenge. You have to get out of the pattern of thinking about keywords and start thinking about personas and topics instead. You'll be writing very early buying-stage content for each persona. This is content designed to drive traffic from people who might be interested in what you have to offer, but don't know about it yet. Here are some examples without me really knowing enough about the product to give "real" suggestions:
Persona: Style Focused Samuel
Interests: Fashion, style, celebrity culture, music
Topic Idea: The Footwear Style Guide for 20016
Details: Contact publicists and send free samples to celebrities and athletes. Show pictures of celebrities, fashionistas and others pushing the trends of footwear. One of the several different "trends" to look out for will be your clients' innovative shoe product. Publish this on a shoe/footwear or fashion blog if you can.
Persona: Price Conscious Carroll
Interests: Family, budgeting, jogging
Topic Idea: Saving Money on Kids' Shoes
Details: Kids wear out and grow out of shoes constantly. Here are a few ideas to keep kiddie footwear expenses from breaking your bank. 1. Once-Upon-a-Child... similar stores. 2. This "innovative" shoe product that will lasts for years, guaranteed (again, I know nothing about the product so...).
The idea is to introduce them to the product and brand by means of addressing their interests and concerns. If you get them to your site, offer a freebie, discount, premium gated content, or something else worth providing their email address for.
Step 1 - Identify the audience segments most likely to be interested in this new, innovative product.Step 2 - Create an audience persona for each of your major segments (2-3 typically). Include things like what they are interested in; where they currently go online to read, watch, socialize and shop; who influences them online; etc...
Step 3 - Write content that both addresses their needs/interests while at the same time featuring this brand and their new footwear product. Preferably, publish the content on a site you have identified as a place where this segment hangs out online (e.g. Jogging forums, fashion blogs...) to reach an audience much bigger than you would by publishing it on your site. The content should try to get them to the site though - usually by peaking their interests for more information, or offering them something of value.
Step 4 - Collect their email address when they come to the site.
Step 5 - Nurture them to a purchase over time through email offers (premium content, discounts, freebies...)
If you need to create demand for a new keyword search, just use it in the content, press releases, etc... and over time some search volume should start to creep up. In the meantime, don't let that keep you from driving qualified traffic to the site with persona-based topic research.
Good luck!